Will It Work? · Guide
USB-C port symbols: what the marks next to a laptop port tell you
By Bulan Sarkar, founder of ElectronicsInfoline (since 2000)
A laptop can have three USB-C ports that look the same and do different things. The small mark printed beside each port is the quickest clue. This guide reads each mark from the groups that own them (the USB-IF, Intel and VESA) and points out what none of them tell you.
A number such as 10Gbps is a USB-IF port logo and gives the port's top data rate. A battery shape is the USB-IF Device Power Port logo, for ports that also passed USB Power Delivery testing. A lightning bolt marks Thunderbolt (Thunderbolt 4 requires 40 Gbps). DP marks DisplayPort video. No mark proves nothing either way: check the laptop maker's spec sheet.
The shape of the port tells you nothing
In the USB-IF's own words, USB Type-C is a type of connector (USB-IF). USB Power Delivery, USB4 and USB 3.2 speeds are each optional on a USB-C product (USB-IF), and a USB 2.0 Type-C port carries data at up to 480 Mbps (USB-IF). Thunderbolt 4 uses the same oval connector (Intel).
So the mark beside the port is what tells them apart, when there is one.
A speed number: the port's top data rate
The USB-IF port logos state the port's signalling capability, such as 5Gbps (USB-IF). They come in five rates: 5, 10, 20, 40, 80 Gbps (USB-IF). A computer maker may print one when the computer's USB chip is certified, even if the computer as a whole is not (USB-IF).
A port marked Hi-Speed is a 480 Mbps port (USB-IF), the USB 2.0 rate. Fine for a mouse or keyboard, slow for an external drive.
A battery shape: the port passed Power Delivery tests
The USB-IF Device Power Port logo may go only on products that passed the USB-IF tests for their data speed, for USB Power Delivery and for USB Type-C (USB-IF). Its shape is a battery with a terminal at one end (USB-IF).
It comes in the same five speeds as the plain port logo (USB-IF), so it carries a data rate, not a wattage. How many watts the port takes in or gives out is on the laptop maker's spec sheet.
A lightning bolt: Thunderbolt
Intel describes Thunderbolt 4 as using the oval USB-C connector with a lightning symbol, and calls the Thunderbolt logo an indicator of what a connection can do (Intel) (Intel). Thunderbolt 4 certification requires power, data and video at a constant 40 Gbps (Intel), and up to two 4K 60 Hz displays or one 8K 60 Hz display (Intel).
A bolt on its own does not say which Thunderbolt version the port is. For the differences between 3, 4 and 5, see Thunderbolt 3, 4, 5 and USB4 compared.
DP letters: video out
VESA, which runs DisplayPort, says USB-C ports that carry DisplayPort will normally have the DP logo near the connector (VESA), and that the device documentation should say so too (VESA).
A missing DP mark is not a “no”. VESA adds that most video sources with a USB-C connector support DisplayPort Alt Mode even when it is not marked (VESA). How many monitors, and at what refresh rate, depends on the lanes and the DisplayPort version, covered in two monitors from one USB-C port.
What the marks leave out
Each mark answers one question. None of them gives charging watts, and only the bolt says anything about displays. The table below sums it up, and the chart after it shows what each kind of port promises once you know what it is.
Tips and tricks
- Take a photo of the marks on your laptop, then open the maker’s spec page and find the “Ports” line. The two together answer most questions.
- If some USB-C ports have a bolt or DP mark and others have none, try a monitor or dock in a marked port first.
- For an external SSD, use the port with the highest speed number. The cable and the drive need that rate too, so check the cable’s speed rating.
- A port marked Hi-Speed runs at 480 Mbps. Keep it for mice, keyboards and dongles.
- An unmarked port may still carry video: VESA says most USB-C video sources support DisplayPort Alt Mode. Test it before buying an adapter.
What we would do
Read the marks first, then confirm on the spec sheet. For a dock with two monitors, use a port with the lightning bolt, or one marked DP, and check the display line on the spec sheet. For fast storage, use the port with the highest speed number. For charging, go by the watts on the spec sheet, since no port mark states them.
Then run your setup through the USB-C hub and dock checker. For the cable side, see USB-C cable ratings.
Questions people ask
What does the lightning bolt next to a USB-C port mean? It marks a Thunderbolt port. Intel describes Thunderbolt 4 as using the oval USB-C connector with a lightning symbol, and Thunderbolt 4 certification requires power, data and video at a constant 40 Gbps.
What does DP next to a USB-C port mean? The port can send DisplayPort video over USB-C (DisplayPort Alt Mode), so a monitor can connect with a USB-C cable or a USB-C to DisplayPort adapter.
What does the battery symbol next to a USB-C port mean? It is the USB-IF Device Power Port logo. A product may carry it only after passing USB-IF tests for its data speed, USB Power Delivery and USB Type-C. It shows a data rate, not a wattage.
Sources
Each figure on this page is quoted from the source below or worked out from them. Sources checked , each quote read again against the source in a second pass.
- USB-IF, USB Type-C® and USB 2.0 Type-C™ Cable and Connector Language Usage Guidelines:
USB Type-C® is a type of connector.
usb.org/sites/default/files/usb_type-c_language_product_and_… - USB-IF, USB Type-C® and USB 2.0 Type-C™ Cable and Connector Language Usage Guidelines:
Device manufacturers can choose to support USB Power Delivery, USB4®, and/or USB 3.2 performance, but it is not required for USB Type-C® products
usb.org/sites/default/files/usb_type-c_language_product_and_… - USB-IF, USB Type-C® and USB 2.0 Type-C™ Cable and Connector Language Usage Guidelines:
Supports up to 480Mbps data operation
usb.org/sites/default/files/usb_type-c_language_product_and_… - USB-IF, USB Performance Logo Usage Guidelines (Jan 2026):
The USB Port Logos may be used by companies with a valid USB-IF Trademark License Agreement on file and indicates the port's signaling capability (i.e. 5Gbps, etc.).
usb.org/sites/default/files/usb_performance_logo_usage_guide… - USB-IF, USB Performance Logo Usage Guidelines (Jan 2026):
USB 5Gbps, USB 10Gbps, USB 20Gbps, USB 40Gbps, and USB 80Gbps Packaging Logos, Port Logos, and Device Power Port Logos
usb.org/sites/default/files/usb_performance_logo_usage_guide… - USB-IF, USB Performance Logo Usage Guidelines (Jan 2026):
The USB Port Logo may be used on End Product Host(s) with certified Si regardless of whether the end product is certified.
usb.org/sites/default/files/usb_performance_logo_usage_guide… - USB-IF, USB Logo Usage Guidelines: Hi-Speed USB and Certified USB Charger (Aug 2026):
The Hi-Speed USB Logo must be used with Hi-Speed (480 Mbps) Product.
usb.org/sites/default/files/usb-if_original_logo_usage_guide… - USB-IF, USB Performance Logo Usage Guidelines (Jan 2026):
The USB Device Power Logo may solely be used in conjunction with products consisting of Host(s), peripheral device(s), or hub(s) that have been submitted to and passed the USB-IF Test procedures for the corresponding performance, USB Power Delivery and USB Type-C® testing requirements
usb.org/sites/default/files/usb_performance_logo_usage_guide… - USB-IF, USB Performance Logo Usage Guidelines (Jan 2026):
The Logo can be oriented horizontally with the battery terminal to the right or vertically with the battery terminal to the top.
usb.org/sites/default/files/usb_performance_logo_usage_guide… - Intel, What Is Thunderbolt 4 and How Is It Different from USB-C?:
Thunderbolt™ 4 uses the oval-shaped USB-C connector type, features a lightning symbol, and is compatible with USB4.
intel.com/content/www/us/en/architecture-and-technology/thun… - Intel, What Is Thunderbolt 4 and How Is It Different from USB-C?:
The Thunderbolt™ logo is a simple, surefire indicator of what a connection between devices can do.
intel.com/content/www/us/en/architecture-and-technology/thun… - Intel, What Is Thunderbolt™ 4 and How Is It Different from USB-C? – Intel:
Thunderbolt™ 4 certification requires support for power, data, and video with constant 40 Gbps bandwidth.
intel.com/content/www/us/en/architecture-and-technology/thun… - Intel, What Is Thunderbolt™ 4 and How Is It Different from USB-C? – Intel:
Up to two 4K 60 Hz displays or one 8K 60 Hz display on a single connection
intel.com/content/www/us/en/architecture-and-technology/thun… - VESA, DisplayPort FAQ:
USB Type-C connectors that support the DisplayPort over USB-C will normally include the DisplayPort (DP) logo near the connector.
displayport.org/faq/ - VESA, DisplayPort FAQ:
This information should be provided by the device documentation. Devices that support DisplayPort Alt Mode may also have the “DP” logo next the connector, in addition to the USB logo.
displayport.org/faq/ - VESA, DisplayPort FAQ:
even if DisplayPort Alt Mode is not identified, most video source devices on the market today that use the USB-C connector already support DisplayPort Alt Mode.
displayport.org/faq/