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WCAG 2.x sRGB Contrast Calculator
x402
WCAG 2.x sRGB Contrast Calculator is a paid API for AI agents from api.zfinia.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).
Calculates the WCAG 2.x sRGB contrast ratio for a caller-supplied pair of foreground and background colours.
Price / call$0.001
Success—
StatusUnknown
How this service works
Calculate WCAG 2.x sRGB contrast for one caller-supplied colour pair; no interface-wide accessibility claim is made.
Output
Returns the computed WCAG 2.x sRGB contrast ratio (a numeric value between 1:1 and 21:1) for the supplied colour pair, along with pass/fail status against standard WCAG compliance thresholds (AA and/or AAA levels for normal and large text).
Example use cases
Checking text readability on brand background
“I want to use #003087 as my text colour on a #F5F5F5 background — can you calculate the WCAG sRGB contrast ratio and tell me if it passes AA or AAA?”
Validating button colour accessibility
“My call-to-action button is #FF6B00 with white (#FFFFFF) text on it — what's the contrast ratio and does it meet WCAG 2.x requirements?”
Dark mode colour pair evaluation
“For our dark mode UI, we're using #E0E0E0 text on a #121212 background — please compute the WCAG sRGB contrast ratio so we know if it's accessible.”
Technical details
Endpoint
POSThttps://api.zfinia.com/x402/v1/accessibility-contrast-calculatorWhen to prefer
Choose this endpoint when you need a fast, deterministic, per-colour-pair WCAG 2.x sRGB contrast ratio calculation without needing a full accessibility audit tool. Ideal for design-time checks, CI pipelines validating colour tokens, or agent workflows that need to programmatically verify individual colour combinations meet minimum contrast thresholds before publishing UI assets.
Side effects
- Invalid colour format provided (e.g. malformed hex or out-of-range sRGB values) — returns validation error
- Missing foreground or background colour in request body — returns bad request error
- Contrast ratio computable but no WCAG level claim made at interface-wide scope — result is per-pair only
- Network or service unavailability — returns 5xx error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| background | string | |
| foreground | string | |
| large_text | boolean |
Output
Schema · Response
{
"type": "json",
"example": {
"wcag_aa": true,
"wcag_aaa": true,
"large_text": false,
"request_id": "example-request",
"service_id": "accessibility_contrast_calculator",
"limitations": [
"Calculation uses WCAG 2.x sRGB contrast; it does not assess full interface accessibility."
],
"contrast_ratio": 21,
"service_version": "1.0.0"
}
}Tags
x402
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