# USB-C cables

Two independent ratings decide what a USB-C cable can do: power (60 W, 100 W or 240 W) and data (USB 2.0 at 480 Mbps up to 80 Gbps), and the data rating decides whether it drives a monitor. Most charging cables are USB 2.0 inside, listings rarely say so, and the only checkable marking is USB-IF's certified logo.

## How it works

A USB-C cable is a bundle of wires behind a 24-pin plug. Five wires always exist: power and ground, the configuration channel the two ends use to agree on voltage and current, and two USB 2.0 data wires carrying 480 Mbps. A full-featured cable adds four high-speed pairs; those carry USB 3 data at 5 to 80 Gbps and, when a laptop asks, a DisplayPort monitor signal instead. Every cable must carry 3 A, which at 20 V is 60 W. To carry 5 A for 100 W or 240 W, the cable must hold an e-marker, a chip in the plug that declares its current, voltage and speed limits. The high-speed pairs lose signal with length, so a passive cable's top speed falls as it gets longer; active cables add chips in the plugs to push further. Nothing on the outside shows which wires or chips are inside. [6] [10] [33] [5] [21]

| Family | What it is | Suits |
|---|---|---|
| USB 2.0 charging cable | Two slow data wires and the power wires. 480 Mbps, 60 W by default, 100 W or 240 W with an e-marker. Cannot carry video. | Charging anything, including laptops when rated for it; syncing a phone slowly. |
| Full-featured USB 3 cable | All high-speed pairs present. 5, 10 or 20 Gbps, and it carries a DisplayPort monitor signal. | External drives, docks, a single monitor. |
| USB4 or Thunderbolt cable | The same pairs built to tighter tolerances for 40 or 80 Gbps under the USB4 standard or Intel's Thunderbolt, usually 100 W or 240 W as well. Passive to about 0.8 m or 1 m, active to 2 m. | Thunderbolt docks, fast SSDs, two monitors, external graphics. |
| USB-C to USB-A or Lightning cable | One end is the older connector, which caps power at about 15 to 18 W and data at the older port's speed. C-to-A cables need a 56 kΩ resistor inside; C-to-Lightning cables need Apple's 'Made for iPhone' (MFi) certification. | Older chargers and car ports; iPhones made before the switch to USB-C. |

## How an expert narrows the choice

```mermaid
timeline
  section 1 · Connector ends
    USB-C to USB-C : skip 56 kΩ resistor (C-to-A cables)
    USB-C to USB-A : ask 56 kΩ resistor (C-to-A cables) : skip Power rating, Carries a monitor signal
    USB-C to Lightning : ask Certification : skip Power rating, 56 kΩ resistor (C-to-A cables)
  section 2 · Data rate
    charge-only, no data wires / USB 2.0, 480 Mbps : skip Carries a monitor signal, Active or passive
  section 3 · Power rating
    up to 60 W (3 A, no e-marker needed) : skip E-marker chip
    100 W (5 A at 20 V, e-marked) / 240 W (5 A at 48 V, Extended Power Range, e-marked) : ask E-marker chip
  section 4 · Cable length
    under a metre : skip Active or passive
    about two metres : ask Active or passive
    longer : skip Active or passive, Carries a monitor signal
```

1. **Connector ends.** USB-C on both ends, or USB-A or Lightning on one?
   Removes a third or more of the catalog and sets the ceiling first. A USB-A end stays at about 15 to 18 W under the USB rules and never carries video; a Lightning end brings its own certification.
   If USB-C to USB-C: skip 56 kΩ resistor (C-to-A cables).
   If USB-C to USB-A: ask 56 kΩ resistor (C-to-A cables); skip Power rating, Carries a monitor signal.
   If USB-C to Lightning: ask Certification; skip Power rating, 56 kΩ resistor (C-to-A cables).
   Skip if already known: devices and chargers the user owns, an earlier answer naming a laptop, or an iPhone with Lightning.

2. **Data rate.** Charging only, or files or a monitor too?
   Charging-only narrows the set to USB 2.0 cables, which are most of the catalog and the cheapest. Files or a monitor need a full-featured cable, which is a different product inside the same-looking jacket.
   If charge-only, no data wires or USB 2.0, 480 Mbps: skip Carries a monitor signal, Active or passive.
   Skip if already known: an earlier mention of an external drive, dock or monitor, memory: the user works from a laptop dock.

3. **Power rating.** Only phones and earbuds, or a laptop too?
   Phones and small devices draw under 60 W, which every USB-C cable carries. Laptops need the 100 W or 240 W classes, which carry an e-marker and are a minority of listings.
   If up to 60 W (3 A, no e-marker needed): skip E-marker chip.
   If 100 W (5 A at 20 V, e-marked) or 240 W (5 A at 48 V, Extended Power Range, e-marked): ask E-marker chip.
   Skip if already known: laptop model in memory, charger wattage in memory.

4. **Cable length.** Under a metre (desk), about two metres (bedside), or longer?
   Last because it only bites together with speed, and the thresholds are the cable's own: under 1 m any speed is available; over 1 m, 40 Gbps needs an active cable; over 2 m only USB 2.0 is within specification.
   If under a metre: skip Active or passive.
   If about two metres: ask Active or passive.
   If longer: skip Active or passive, Carries a monitor signal.
   Skip if already known: a desk or bedside setup described earlier.

## What to surface

### Connector ends

Which plug is on each end of the cable. The older end sets the ceiling. Under USB rules a USB-A end carries about 15 W from a USB 3 port, or 18 W with Quick Charge, never USB Power Delivery and never video, so a 'fast charging' C-to-A cable cannot charge a laptop; only OPPO's proprietary SuperVOOC cables go higher, with their own charger and phone. A C-to-A cable also needs a 56 kΩ resistor inside. A Lightning end needs Apple's MFi certification to charge reliably and not overheat. [28] [25] [27] [12] [31] [38] [39]

Values: USB-C to USB-C, USB-C to USB-A, USB-C to Lightning, USB-C to other (micro-USB, HDMI, DisplayPort, 3.5 mm).
Question to ask: USB-C on both ends, or USB-A or Lightning on one?

Used as: top-level split, filter. Data: on the listing, backfill cost none. Look for it as: In the title and in two connector fields; the add-on keeps them as connector_a_raw and connector_b_raw.

### Cable length

How long the cable is from plug to plug. Length is harmless for charging and costly for speed. A passive cable holds 40 Gbps only to 0.8 m, 10 Gbps to 1 m, 5 Gbps to 2 m and USB 2.0 to 4 m, and a cable that is too long for its rating drops to a lower speed silently rather than failing. Long cables at full speed are active cables with chips in the plugs, which cost more and sometimes lose older USB modes. [6] [10] [9] [11] [8] [30] [7]

Range: 0.3 to 4 m. Most cables sell at about 1 m and 2 m. Passive Thunderbolt and USB4 cables cluster at 0.3 to 1 m; 3 m is sold for charging only.
Question to ask: Under a metre (desk), about two metres (bedside), or longer?

Used as: top-level split, filter, sortable. Data: on the listing, backfill cost none. Look for it as: In the title in feet or metres and in a length field; the add-on stores length_ft.
Chart: Length versus speed step chart.

### Data rate

The fastest data the cable's wires are built to carry, from none at all to 80 Gbps. This rating separates a cheap charging cable from one that runs a drive or monitor, and listings most often leave it out. USB 2.0 cables have no high-speed wires, so they cannot carry a monitor signal, and copying a 20 GB file takes over 9 minutes against under 30 seconds at 40 Gbps. Some cables have no data wires and only charge. Apple's, Anker's and Belkin's 240 W cables are all USB 2.0 inside, so wattage says nothing about speed. [6] [10] [9] [19] [23] [20] [21] [16] [24] [29] [36]

Values: charge-only, no data wires, USB 2.0, 480 Mbps, 5 Gbps (USB 3.2 Gen 1), 10 Gbps (USB 3.2 Gen 2), 20 Gbps (USB 3.2 Gen 2x2 or USB4 Gen 2), 40 Gbps (USB4 or Thunderbolt 3 and 4), 80 Gbps (USB4 version 2 or Thunderbolt 5).
Question to ask: Charging only, or files or a monitor too?

Used as: top-level split, filter, sortable. Data: derived from listing fields, backfill cost low. Look for it as: In the title or bullets as 'USB 2.0', '480Mbps', 'USB 3.2 Gen 2', '10Gbps', 'USB4', 'Thunderbolt 4' or '40Gbps'; the add-on keeps the raw string as spec_version_raw. Absent on most C-to-C cables sold by wattage.
Parse the listing string when one exists, which is the minority of cables sold for data. For the rest, derive: a C-to-C cable that states a wattage and no speed is USB 2.0, because every leading brand's wattage-only cable is USB 2.0 and the logo rules let such cables omit a data marking. When nothing is stated and the title says 'charging cable', record charge-only as possible and flag it. A tester that reads the e-marker settles it; use one for the top 200 cables.
Chart: Length versus speed step chart.

### Power rating

The most power the cable is rated to carry, which USB-IF groups into 60 W, 100 W and 240 W classes. Every USB-C cable must carry 3 A, which is 60 W at 20 V, so any cable charges a phone at full speed. Above that the cable needs an e-marker: 100 W cables carry 5 A at 20 V and 240 W cables 5 A at 48 V under Extended Power Range. A 240 W cable's e-marker must declare 50 V and 5 A; that is how the charger learns it may go above 20 V. [6] [5] [2] [33] [12] [35]

Values: up to 60 W (3 A, no e-marker needed), 100 W (5 A at 20 V, e-marked), 240 W (5 A at 48 V, Extended Power Range, e-marked).
Question to ask: Only phones and earbuds, or a laptop too?

Used as: top-level split, filter, sortable. Data: on the listing, backfill cost low. Look for it as: Almost always in the title as '60W', '100W' or '240W'; the add-on stores it as power_delivery_watts. Odd values such as 65 W or 140 W belong to the next class up.
When missing on a C-to-C cable, record 60 W; the specification guarantees it. Never infer higher.
Chart: USB-IF certified cable logo.

### Carries a monitor signal

Whether the cable can carry a DisplayPort monitor signal, which rides on the same high-speed wires as USB 3 data. A USB 2.0 cable has no high-speed wires, so it cannot drive a monitor even though the plug fits. Any cable rated 5 Gbps or more can. Listings that say '4K@60Hz' or '8K' are stating this; listings that say 'does not support screen mirroring' are stating the opposite. [10] [6] [23] [19]

Question to ask: Will this cable ever drive a monitor?

Used as: filter, shown on the card. Data: derived from listing fields, backfill cost none. Look for it as: Derive from data_rate. Bullets saying '4K', '8K', 'DisplayPort', 'video' or 'does not support screen mirroring' confirm it.

### Certification

Whether an outside body has tested the cable against its claims: USB-IF for USB-C, Intel for Thunderbolt, Apple's MFi for Lightning. Nothing on a cable's outside proves what is inside, and reviewers keep finding labels wrong in both directions. The USB-IF logo on the overmold is the one marking a test lab checked, and it prints the power and data rating together. Intel certification covers Thunderbolt cables; MFi covers Lightning cables, which can otherwise overheat or refuse to charge. Most cables on big marketplaces are not in the USB-IF registry at all, which says nothing against any one cable. [1] [3] [4] [13] [31] [32] [29]

Values: USB-IF certified, found in the registry, USB-IF certified, claimed on the listing, Thunderbolt certified (Intel), MFi certified (Lightning cables), no certification claimed.

Used as: filter, shown on the card. Data: needs research, backfill cost high. Look for it as: 'USB-IF Certified', '[Intel Certified]' or 'MFi Certified' in the title, or a 'Specification Met' field. The claim is on the listing; the verification is not.
Look the model up in the USB-IF Product Search at usb.org/products by model or company and store the test ID. Do this for the top 200 cables and lazy-load the rest; record 'claimed' when the registry does not list it.
Chart: USB-IF certified cable logo.

### Magnetic tip

Whether the cable ends in a detachable magnetic tip that stays in the device's port. Magnetic tips leave the port's pins exposed, and a staple, a damp room or static from a carpet can bridge pins that must never touch and spike the device. They sit outside the USB-C specification, so none of the safeguards built into real connectors apply. Reviewers who test cables say not to buy them, so this document excludes them by default and lets the buyer opt in. [17] [18]


Used as: filter, shown on the card. Data: on the listing, backfill cost none. Look for it as: 'Magnetic' in the title.

### Active or passive

Whether the cable is plain wire (passive) or has signal-boosting chips in its plugs (active) so it can hold full speed over a longer run. This only matters above about 1 m at 40 Gbps or more. Passive 40 Gbps cables top out at 0.8 m; active ones reach 2 m. Active cables cost more, and active Thunderbolt 3 cables carry Thunderbolt only and not plain USB, so an active cable is not a universal cable. [8] [7] [11]

Values: passive, active.

Used as: filter, shown on the card. Data: derived from listing fields, backfill cost low. Look for it as: 'Active' appears in the title when it is a selling point; otherwise unstated. Any 40 Gbps cable sold at 2 m is active or mislabelled.
Derived from speed and length: 40 Gbps or 80 Gbps and longer than 1 m means active; otherwise passive. 'Active' in the title confirms it. Check the brand page for the top 100.
Chart: Length versus speed step chart.

### E-marker chip

A chip inside the plug that tells the charger and device the cable's current, voltage and speed limits. Without an e-marker a charger will not send more than 3 A whatever the listing claims, because there is nothing to negotiate with. The specification requires one in every cable above 60 W or above USB 2.0, so its presence is implied by those ratings, and its absence on a cable claiming them means it is out of specification. Reviewers read the chip to check listings; Windows does not expose it, and a tester costing under 100 dollars does. [6] [33] [5] [15] [34]


Used as: shown on the card. Data: derived from listing fields, backfill cost low. Look for it as: Sometimes a bullet reads 'E-Marker chip' or 'E-Mark'. Otherwise implied by a 100 W, 240 W, or 5 Gbps and up rating.
Set true when power_rating is 100 W or 240 W or data_rate is 5 Gbps or more. Testers that read the chip cost under 100 dollars; use one on the top 200 cables to catch fakes.

### Jacket material

What the outside of the cable is made of. The jacket decides how the cable survives bending and how it feels, not what it can do electrically. Braided nylon or polyester resists abrasion and kinks and is what most premium cables use; silicone is the softest and tangles least but cuts more easily; TPE (a rubbery plastic) and PVC (a stiffer vinyl) are the cheap defaults. Belkin and Anker sell braided and silicone versions of the same rating, so this is a preference, not a performance choice. [26] [27] [23] [37]

Values: braided nylon or polyester, silicone, TPE, PVC.
Question to ask: Braided, soft silicone, or plain plastic?

Used as: shown on the card, filter. Data: on the listing, backfill cost low. Look for it as: In the title ('Braided', 'Silicone', 'Soft') and in a jacket or material field. Braided against smooth is also visible in the product photo.
Braided against smooth comes from the photo. Silicone against TPE does not; when unstated record unknown.

### 56 kΩ resistor (C-to-A cables)

For USB-C to USB-A cables only, whether the cable contains the 56 kΩ resistor the standard requires. The resistor tells the phone what a USB-A charger can give; a wrong or missing one lets the phone pull 3 A from a port that cannot supply it and can destroy the port or the charger. In one test of 43 older C-to-A cables, 10 were built wrong. Brands that got it right say so in the title, which is why '56K ohm' appears in listings at all. [12] [13] [14] [25]


Used as: filter, shown on the card. Data: needs research, backfill cost medium. Look for it as: Appears as '56K' or '56k ohm resistor' in the title or bullets only when a brand chooses to say so; most C-to-A listings are silent, and Anker's figure sits in a support FAQ, not the listing.
C-to-A cables only. A listing that states it can be recorded as stated; silence means unknown, not absent. A cable tester reads the resistor in seconds, so test the top 50 C-to-A cables and lazy-load the rest.

### Bend-cycle rating

The number of bends the brand says the cable survived in its own test. It shows the brand tested at all, but the numbers do not compare across brands: Anker rates a 240 W braided cable at over 30,000 bends and Belkin rates its equivalent at over 350,000, and neither publishes the method. Within one brand's range a higher number usually marks the sturdier line. [23] [26] [27] [19] [40]

Range: Belkin's lines claim 25,000 to 350,000 and up, against 1,000 for what Belkin calls an ordinary PVC cable; Anker's braided cables claim over 30,000.

Used as: shown on the card. Data: on the listing, backfill cost none. Look for it as: A 'Bend Lifespan' or 'Bend Test' field, or a bullet such as '30,000+ bends'.
Kept as a listing field because only brands that run the test (Anker, Belkin) publish a number, and they put it in a spec field. Absence means not stated, never zero. Do not sort on it.

## Numbers worth computing

| Metric | Formula | Why |
|---|---|---|
| Honest speed at this length (Gbps) | `if active_or_passive == active then data_rate else min(data_rate, passive_ceiling(cable_length)); passive_ceiling is 40 Gbps to 0.8 m, 10 Gbps to 1 m (20 Gbps to 1 m for USB 3.2 Gen 2x2, to 2 m for USB4 Gen 2), 5 Gbps to 2 m, 480 Mbps to 4 m` | The speed a buyer will get, not the one on the box. Listings quote the rating without the length it holds at, and a too-long passive cable drops speed silently. [9] [10] [11] [6] |
| Claim exceeds passive limit (flag) | `data_rate > passive_ceiling(cable_length) and active_or_passive != active` | Catches listings that cannot be true as stated, such as a 2 m passive '40 Gbps' cable. Reviewers find these; the pipeline can flag them without a tester. [15] [8] |
| E-marker required by the ratings (boolean) | `power_rating > 60 W or data_rate >= 5 Gbps` | What the specification demands inside the plug. If a listing claims these ratings and a tester finds no chip, the listing is false. [6] [33] |

## What you give up

- A long cable is fine for charging and costly for data. Past 0.8 m you lose 40 Gbps unless the cable is active, past 1 m you lose 10 Gbps, and past 2 m you are down to USB 2.0 within the specification. [9] [10] Board branch: "See more short full-speed cables".
- A 40 or 80 Gbps cable has all its high-speed wires built to tight tolerances, so it is thicker, stiffer, shorter and several times the price of a USB 2.0 cable that charges just as fast. Buy it for the dock or the drive, not for the bedside. [15] [19] [20] Board branch: "See more thin charging-only cables".
- A 240 W cable needs heavier conductors and an e-marker, so it is thicker and stiffer than a 60 W cable of the same length; Apple's 2 m 240 W cable weighs 78 g. Phones and earbuds never use the headroom, so for a bedside cable the 60 W class is lighter and cheaper. [20] [5] Board branch: "See more light phone cables".
- An active cable holds 40 Gbps to 2 m, but active Thunderbolt 3 cables carry Thunderbolt only and not plain USB, and active cables cost more. Keep a short passive cable for everything else. [8] Board branch: "See more passive cables".
- A magnetic tip saves wear on the port and risks the whole device. Reviewers who test cables say the trade is not worth it. [17] [18] Board branch: "See more cables with a standard plug".
- Braided jackets resist abrasion and kinks; silicone is softer and tangles less but cuts more easily. Neither changes what the cable can do. [37] [27] Board branch: "See more soft silicone cables".

## How to draw it

**USB-IF certified cable logo** (swatch grid, shows Power rating, Data rate, Certification). One badge that prints the power class (60 W or 240 W) and the data rate (5 to 80 Gbps) together, so a buyer sees both ratings and that a lab checked them. USB 2.0 cables carry a wattage-only version, which is itself a tell. Used today by USB-IF, printed or embossed on the overmold of every certified USB-C to USB-C cable since 2021. [1] [2] [3] [22]

**Length versus speed step chart** (two axis map, shows Cable length, Data rate, Active or passive). Length along the bottom, speed up the side, with the passive ceiling drawn as steps at 0.8 m, 1 m, 2 m and 4 m and a higher line for active cables. A cable plotted above the step line is claiming more than passive wire can carry. Used today by Plugable, Adafruit and chip makers' knowledge bases, as tables; the step chart itself is our proposal. [10] [7] [9]

## Words you will meet

- **USB-C**. The oval, reversible plug; it says nothing about what the cable behind it can do.
- **USB Power Delivery (PD)**. The rulebook the charger and device use to agree on voltage and current over the cable.
- **Extended Power Range (EPR)**. The part of USB Power Delivery that allows up to 48 V and 240 W and requires a cable marked for it.
- **E-marker**. A chip in the plug that reports the cable's current, voltage and speed limits.
- **Full-featured cable**. A USB-C cable with all its high-speed wires, so it can carry USB 3 data and a monitor signal.
- **USB 2.0 cable**. A USB-C cable with only the two slow data wires; it charges fine and moves data at 480 Mbps.
- **Charge-only cable**. A cable with power wires and no data wires at all.
- **Passive cable**. Plain wire from plug to plug; speed falls as length rises.
- **Active cable**. A cable with chips in the plugs that keep the signal clean over a longer run.
- **DisplayPort Alternate Mode**. The arrangement that sends a monitor signal over the high-speed wires of a full-featured cable.
- **USB4**. The USB standard that runs at 40 Gbps, or 80 Gbps in version 2, over USB-C.
- **Thunderbolt**. Intel's standard that shares the USB-C plug and runs at 40 Gbps (versions 3 and 4) or 80 Gbps (version 5).
- **Gen 1, Gen 2, Gen 2x2**. USB's names for 5, 10 and 20 Gbps.
- **USB-IF certified**. Tested by the USB standards body's programme and listed in its public registry.
- **MFi**. Apple's 'Made for iPhone' licence, needed for a Lightning cable to work reliably.
- **56 kΩ resistor**. The part inside a USB-C to USB-A cable that tells the phone how much current a USB-A charger can give.
- **Overmold**. The moulded plastic around the plug, where the certification logo is printed.

## Where we made a call

- Passive 40 Gbps cables hold full speed only to 0.8 m; Thunderbolt 4 cables sold longer at 40 Gbps are active or specially qualified. (confidence high). Sources disagree. Plugable's blog and Wikipedia put the passive line at 0.8 m, Adafruit at 1 m for Thunderbolt 4, and Plugable's table allows Thunderbolt 4 to 2 m without saying passive. We use 0.8 m because every source accepts it and the longer figures describe certified or active cables. [8] [7] [10] [6]
- The passive length ceilings are 4 m for USB 2.0, 2 m for 5 Gbps and 1 m for 10 Gbps. (confidence high). Sources disagree. Adafruit gives 5 m, 3 m and 0.8 m. Wikipedia, Plugable's knowledge base and Plugable's 2026 explainer give 4, 2 and 1 m, which match the USB-C specification's figures, so we side with them. [6] [10] [9] [7]
- A USB-C to USB-C cable that states a wattage and no data rate is a USB 2.0 cable. (confidence high). Apple's, Anker's and Belkin's 240 W cables are all USB 2.0 inside, and USB-IF's logo rules let USB 2.0 cables omit any data marking. Treat the default as 480 Mbps and never as faster. [20] [21] [23] [1]
- Bend-cycle counts are not comparable across brands. (confidence high). Anker claims over 30,000 and Belkin over 350,000 for cables of the same class, with no published method. Show the number, never rank on it. [23] [26]
- The only claim on a cable a buyer can verify without a tester is certification, and most marketplace cables are not in the USB-IF registry. (confidence medium). One walkthrough from December 2023 found most popular marketplace cables missing from the registry. We keep 'claimed' and 'found' as separate values rather than treating absence as fraud. [4] [1]
- Phone fast-charging protocols on a cable listing (PPS, Quick Charge, SuperVOOC) describe the charger, not the cable. (confidence medium). The e-marker reports current, voltage, speed and whether the cable is active; the resistor in a C-to-A cable reports the charger's capability, not the cable's. Any cable rated for the current passes the protocol. This reading is ours. [33] [12]
- Magnetic-tip cables should be excluded by default. (confidence high). Two reviewers list the same failure modes: exposed pins, debris and static bridging, arcing on disconnect, and no place in the specification. [17] [18]
- Braided jackets outlast smooth ones, and silicone is the softest but cuts most easily. (confidence low). The only ranked numbers come from a manufacturer-side marketing guide with no method. We keep jacket as a preference annotation, not a durability score. [37]
- A 40 Gbps claim on a cable longer than 0.8 m that does not say active should be flagged as suspect rather than dropped. (confidence medium). Some such cables are active without saying so and some are mislabelled; reviewers found both. The derived check flags; a tester settles it for the top of the catalog. [15] [16]

## References

1. [USB Type-C Cable Logo Usage Guidelines (USB-IF, 2024)](https://www.usb.org/sites/default/files/usb_type-c_cable_logo_usage_guidelines_20240903.pdf) (standards body). Supports: Certified USB-C to USB-C cables must carry a combined data-rate and wattage logo on the overmold; USB 2.0 cables carry a wattage-only logo and need not state data rate; Logo families are 60 W and 240 W by 5, 10, 20, 40 and 80 Gbps.
2. [USB-IF Announces New Certified USB Type-C Cable Power Rating Logos (30 Sep 2021)](https://www.usb.org/sites/default/files/2021-09/USB-IF_Cable%20Power%20Rating%20USB4%20Logo%20Announcement_FINAL.pdf) (standards body). Supports: The two power classes on certified cable logos are 60 W and 240 W, defined by USB PD 3.1; USB-IF's own advice is to look for the certified logo on the cable or packaging.
3. [USB-IF: Cables and Connectors](https://www.usb.org/cable_connector) (standards body). Supports: All USB-C to USB-C cables must be labelled 60 W or 240 W; All cables except USB 2.0 must be marked with their data rate.
4. [GIGAZINE: List of USB cables that show which products are certified by USB-IF (Dec 2023)](https://gigazine.net/gsc_news/en/20231202-usb-if-product-search) (other). Supports: Certification can be checked in the USB-IF Product Search by model or company; Most popular marketplace cables checked were not in the registry.
5. [Granite River Labs: Introduction to PD 3.1](https://www.graniteriverlabs.com/en-us/technical-blog/usb-power-delivery-specification-3-1) (primer). Supports: EPR raises the ceiling from 100 W to 240 W at 48 V and 5 A; EPR cables must contain an e-marker set to EPR capable, 50 V and 5 A.
6. [Wikipedia: USB-C, Cables section](https://en.wikipedia.org/wiki/USB-C) (primer). Supports: Every USB-C cable must support 3 A and up to 20 V; All cables except USB 2.0 at 3 A must contain an e-marker; USB 2.0 cables lack SuperSpeed wires; Passive ceilings of 2 m for Gen 1, 1 m for Gen 2 and 0.8 m for 40 Gbps; EPR is 5 A at higher voltage for up to 240 W.
7. [Adafruit: Understanding USB Type-C, Cable Lengths](https://learn.adafruit.com/understanding-usb-type-c-cable-types-pitfalls-and-more/cable-lengths) (primer). Supports: Faster cables must be shorter; 0.8 m ceiling for USB4 passive; Thunderbolt 4 copper cables up to 1 m are passive, longer are active (the disagreeing figure).
8. [Plugable: What's the difference between active and passive Thunderbolt cables](https://plugable.com/blogs/news/what-s-the-difference-between-active-and-passive-thunderbolt-cables) (primer). Supports: Passive Thunderbolt cables carry 40 Gbps under 0.8 m and 20 Gbps over; Active cables carry 40 Gbps to 2 m; Active Thunderbolt 3 cables carry Thunderbolt only, not USB.
9. [Plugable: Decoding USB Standards, 2026 edition](https://plugable.com/blogs/news/decoding-usb-standards-2026) (primer). Supports: Gen 1x1 is 5 Gbps, Gen 2x1 10 Gbps, Gen 2x2 20 Gbps, USB4 40 or 80 Gbps; Passive guidance of 2 m for 5 Gbps and 1 m for 10 and 20 Gbps; Passive USB4 40 Gbps cables are limited to 0.8 m.
10. [Plugable Knowledge Base: USB Type-C cable compatibility, length and features](https://kb.plugable.com/usb-c-cables/usb-type-c-cable-compatibility-length-and-features) (primer). Supports: USB-C charging cables carry only USB 2.0 data and no video; Data cables at 5 Gbps and up carry USB 3 data or DisplayPort video; Lengths: 4 m USB 2.0, 2 m Gen 1, 1 m Gen 2, 0.8 m USB4, 2 m Thunderbolt 4.
11. [USB4 cable length limits: 0.8 m for 40 Gbps, 2 m for 20 Gbps](https://asmr.education/faq/usb-c/usb4-cable-max-length-passive-active) (primer). Supports: Passive USB4 holds 40 Gbps to 0.8 m and 20 Gbps to 2 m; A too-long passive cable falls back to a lower speed silently; Active USB4 cables reach 2 m at 40 Gbps.
12. [ChromiumOS developer library: USB Type-C cable and adapter tips and tricks](https://www.chromium.org/chromium-os/developer-library/reference/hardware/cable-and-adapter-tips-and-tricks/) (other). Supports: C-to-A cables must use the 56 kΩ pull-up; it signals the power adapter's capability, not the cable's; Using the 3 A resistor is unsafe because a weak adapter can overheat; All cables must support 3 A.
13. [Laptop Mag: How to buy USB Type-C cables that won't fry your gadgets](https://www.laptopmag.com/articles/how-to-find-safe-usb-type-c-cables) (specialist review). Supports: A wrong resistor makes the phone draw 3 A from a weak source and can cause permanent damage; Benson Leung's testing destroyed a Pixel C's USB ports; USB-IF certification is the buyer's check.
14. [PCWorld: We tested 43 old USB-C to USB-A cables. 1 was great. 10 were dangerous](https://www.pcworld.com/article/1063892/we-tested-43-old-usb-c-to-usb-a-cables-1-was-great-10-were-dangerous.html) (specialist review). Supports: 10 of 43 C-to-A cables had a wrong (22 kΩ) or missing 56 kΩ resistor or wrong wiring; A consumer cable checker detects the resistor and wiring.
15. [PCWorld: The best USB-C cables for charging and data transfers, with how we test](https://www.pcworld.com/article/395115/the-best-usb-c-cables-for-charging-and-transferring-data.html) (specialist review). Supports: Reviewers verify cables with a cable checker, an e-marker reader, a milliohm meter and a load test; One tested cable falsely advertised 10 Gbps and the wrong length; Reaching 40 Gbps requires a shorter cable.
16. [PCWorld: I tested every USB-C cable I own. Half weren't worth keeping](https://www.pcworld.com/article/3175338/i-audited-my-usb-cables-with-this-50-tester-and-was-surprised-how-bad-some-of-them-are.html) (specialist review). Supports: A cable in the wild had no data wires at all; A cable labelled USB 3.1 Gen 1 tested as USB4 and 100 W, so labels err both ways.
17. [PCWorld: Don't buy these dangerous USB-C accessories](https://www.pcworld.com/article/2307079/dont-buy-these-dangerous-usb-c-accessories.html) (specialist review). Supports: Magnetic adapters risk static discharge, interference, arcing in humidity and debris shorts; Magnetic adapters are not part of the USB-C specification.
18. [How-To Geek: Stop using magnetic USB-C cables, they can kill your device](https://www.howtogeek.com/stop-using-magnetic-usb-c-cables-they-can-kill-your-device/) (primer). Supports: Bridged pins can create a voltage spike that destroys the device; Magnets attract metallic debris that can bridge pins.
19. [TechGearLab: The best USB-C cables](https://www.techgearlab.com/topics/electronics/best-usb-c-cable) (specialist review). Supports: Reviewers measure charging rate, test video output and time large file copies; A 20 GB copy takes under 30 s at 40 Gbps and over 9 min at 480 Mbps; Durability is judged by strain relief, sheath and repeated bending.
20. [ChargerLAB: Teardown of Apple 240W USB-C Charge Cable (A2794)](https://www.chargerlab.com/teardown-of-apple-240w-usb-c-charge-cable-a2794) (specialist review). Supports: Apple's 240 W cable is USB 2.0 for data; It uses an Infineon CYPD2803 e-marker; At 2 m it weighs 78 g and is 4.6 mm thick; Teardowns do not report wire gauge.
21. [ChargerLAB: Teardown of Belkin 240W Dual USB-C Braided Cable](https://www.chargerlab.com/teardown-of-belkin-240w-dual-usb-c-braided-cable) (specialist review). Supports: Belkin's 240 W cable is USB 2.0 for data with five cores: power, ground, D+, D- and CC; It carries an e-marker and a thermistor at each end.
22. [ChargerLAB: New rating logo, teardown of Baseus 240W USB-C cable](https://www.chargerlab.com/new-rating-logo-teardown-of-baseus-240w-usb-c-cable/) (specialist review). Supports: The USB-IF rating logo appears on real retail cables; A Hynetek HUSB332B e-marker covers 240 W and 40 Gbps in a 1 m cable.
23. [Anker USB-C to USB-C Cable (240W, Upcycled-Braided) product page](https://www.anker.com/products/a82e2-240w-usb-c-to-usb-c-cable) (spec sheet). Supports: Anker publishes MAX Output, Cable Type, Cable Length, Compatibility, Bend Lifespan and Specification Met; The 240 W cable is 480 Mbps and does not support screen mirroring; Bend lifespan claimed as over 30,000.
24. [Anker: Do all USB-C cables transfer data?](https://www.anker.com/blogs/cables/are-all-usb-c-cables-data-cables) (primer). Supports: Charge-only USB-C cables have two wires and no data lines; Speed ladder of 480 Mbps, 5, 10 and 40 Gbps.
25. [Anker support: USB-A to USB-C cable FAQ](https://service.anker.com/article-description/Anker-USB-A-to-USB-C-Cable-FAQ) (spec sheet). Supports: Anker's C-to-A cables contain the 56 kΩ resistor; C-to-A charging tops out at 18 W with Quick Charge or 5 V 2 A otherwise.
26. [Belkin BoostCharge Pro Braided USB-C Cable 240W, 1 m product page](https://www.belkin.com/p/usb-c-to-usb-c-braided-cable-240w-3.3ft%2F1m-white/CAB025fq1MWH.html) (spec sheet). Supports: Belkin publishes wattage, jacket, length, bend test, plug-in count, Intertek certification numbers and warranty; no USB-IF claim; Bend test claimed as 350,000 and up; The 240 W page states no data rate.
27. [Belkin BoostCharge Pro Flex USB-A to USB-C Cable, 15W product page](https://www.belkin.com/p/usb-a-to-usb-c-cable-15w/CAB010bt1MBK.html) (spec sheet). Supports: A C-to-A cable is sold as a 15 W, USB 2.0 cable; Double-braided nylon with silicone jacket; 30,000 and up bends.
28. [BGR: Can a USB-A to C cable fast-charge your device?](https://www.bgr.com/2258027/can-usb-a-to-c-cable-fast-charge-device/) (primer). Supports: USB-A ports max out around 2.5 W for USB 2.0 and 15 W for USB 3.0.
29. [Plugable Thunderbolt 5 Cable 80Gbps (1 m) product page](https://plugable.com/products/tbt5-240w1m) (spec sheet). Supports: A passive 80 Gbps cable is sold at 1 m with 240 W; It carries both Thunderbolt and USB-IF certification.
30. [Thunderbolt Technology: Thunderbolt 5 80/120 Gbps 0.8 m / 1 m passive EPR 240 W cable](https://www.thunderbolttechnology.net/product/thunderbolt-5-80120gbps-08m%EF%BC%8F1m-passive-epr240w-cable) (spec sheet). Supports: Passive 80 Gbps cables are offered at 0.8 m and 1 m; Thunderbolt 5 is 80 Gbps with 120 Gbps boost and 48 V 5 A.
31. [Apple Support: Identify counterfeit or uncertified Lightning connector accessories](https://support.apple.com/en-us/111103) (other). Supports: Apple recommends MFi-badged accessories; Uncertified Lightning cables can damage the device, overheat or fail to fit.
32. [Wikipedia: MFi Program](https://en.wikipedia.org/wiki/MFi_Program) (primer). Supports: MFi is Apple's licensing programme for peripherals; Lightning added protocols that can only be certified through MFi.
33. [USB Connection Information: USB-C eMarker chips explained](https://usbconnectioninformation.com/guides/usb-c-cable-emarker-chips/) (primer). Supports: E-marker declares max current (3 or 5 A), voltage (20 or 50 V), data rate, passive or active, vendor; An e-marker is required above USB 2.0 or above 60 W; macOS exposes e-marker data; Windows does not.
34. [Treedix USB cable tester with eMarker reading](https://treedix.com/products/treedix-usb-cable-tester-usb-c-cable-tester-usb-tester-for-data-transmission-and-power-transmission-cable-testing-resistor-testing-type-c-emarker-for-usb-a-micro-b-micro-b-3-0-type-c-lighting-mini-b) (spec sheet). Supports: Consumer testers read the e-marker's current, voltage and data rate and detect USB 2.0 against USB 3.2 wiring.
35. [MakeUseOf: I stopped buying random USB-C cables after learning what three numbers actually mean](https://www.makeuseof.com/i-learned-three-usb-c-numbers-specs-actually-mean/) (primer). Supports: Data speed and charging speed on a cable are independent ratings.
36. [Target search results: USB-C cable 240W](https://www.target.com/s?searchTerm=usb+c+cable+240w) (retail listing). Supports: Mass-market listings carry wattage, length and jacket in the title and no data rate.
37. [Alibaba seller guide: USB cable material durability comparison](https://seller.alibaba.com/blogs/2026/southeast-asia/electronics-accessories/usb-cable-material-durability-comparison-alibaba-b2b-guide) (other). Supports: Rough ordering of jacket durability: braided above silicone above TPE; silicone cuts easily (low confidence, no method).
38. [Wikipedia: VOOC](https://en.wikipedia.org/wiki/VOOC) (primer). Supports: VOOC cables come in 6.5 A, 10 A and 13.7 A variants; The highest SuperVOOC rates require the bundled proprietary charger and cable.
39. [Flipkart: OPPO DL129 USB-A to USB-C 8 A SUPERVOOC cable, up to 80 W (11 V, 7.3 A)](https://www.flipkart.com/oppo-usb-type-c-cable-8-1-m-dl129-supervooc-vooc-qc-data-usb-a-usb-c/p/itmee3410291af95) (retail listing). Supports: OPPO sells a USB-A to USB-C cable rated for 80 W under its proprietary SuperVOOC scheme.
40. [Belkin BoostCharge Flex USB-C to USB-C Cable 60W product page](https://www.belkin.com/p/usb-c-to-usb-c-cable-60w/P-CAB009.html) (spec sheet). Supports: Claims 25,000 and up bends from an internal laboratory test, against 1,000 for an ordinary PVC cable.