Colour contrast

Live

Does this text colour pass WCAG AA on that background?

Contrast ratio and AA/AAA for normal and large text. Hosted — no Photoshop plugin.

Server URL

streamable http

https://toolcargo.com/mcp/color-contrast

Claude Code

terminal

claude mcp add --transport http --scope user toolcargo-color-contrast https://toolcargo.com/mcp/color-contrast \
  --header "Authorization: Bearer YOUR_API_KEY"

Create a key in your dashboard. Other clients: setup guides.

What it helps you do

Ratio :1
AA and AAA pass/fail

Built for: Designers and marketers checking brand colours on the web.

Example requests

Button text

“Check contrast #ffffff on #b8321a with ToolCargo.”

Ratio and which WCAG bars it clears.

Step-by-step workflows: pre-launch check · fixing link previews

Tools

Tool	What it does	Access
`check_contrast` Check colour contrast	WCAG 2 contrast ratio between two hex colours, with AA and AAA for normal and large text.	Read-only

Requirements

• A ToolCargo account with Site Audit activated (free).

Limitations

• Two solid colours only. Not a page crawler.

Supported clients

“Tested” means we connected that client to this endpoint and ran a tool call ourselves. “Documented” means the client supports this setup per its own docs, but we have not tested it yet.

Claude Code	API key header	Tested	Remote HTTP server with an Authorization header. Tested 2026-09-11 (v2.1.268).
Claude (claude.ai)	OAuth sign-in	Tested	Custom connector with OAuth sign-in; tested on claude.ai web 2026-09-11. Desktop and mobile use the same account connectors but were not tested separately.
Cursor	API key header	Documented, not yet tested	mcp.json with url and headers.
VS Code (Copilot agent mode)	API key header	Documented, not yet tested	.vscode/mcp.json with type http and headers.
ChatGPT (developer mode)	OAuth sign-in	Documented, not yet tested	Requires OAuth; API keys cannot be entered.
MCP Inspector	API key header	Tested	CLI mode, tested 2026-09-11. Useful for calling tools directly.

Pricing

Free

For trying the connector on your own sites.

50 calls/month · 25 links per check

Pro

$12/mo

For freelancers and agencies auditing client sites every week.

2,000 calls/month · 100 links per check

Proposed test price. See the pricing page for checkout status.

Full pricing and billing details