WCAG contrast ratio between two colors — the check the URL-based a11y endpoint c
WCAG contrast ratio between two colors — the check the URL-based a11y endpoint can't do. Give a foreground and background color (hex or rgb()); returns the exact ratio and AA/AAA pass/fail for normal text, large text, and UI components, with a plain-English verdict. ?fg=&bg=
Answeringour last check, 2026-10-10
1 of 1checks answered this week
232 msmedian answer time
$0.001listed price per call
$0.001price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
GET https://api.webbersites.com/api/a11y/contrast
| Category | Everything else |
|---|---|
| Provider host | api.webbersites.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 2 from 2 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-10-10 | valid payment request | 402 | $0.001 | 232 ms |
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"bg": "#ffffff",
"fg": "#767676"
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"properties": {
"bg": {
"description": "Background color \u2014 hex or rgb()",
"type": "string"
},
"fg": {
"description": "Foreground/text color \u2014 hex (#111 or #111111) or rgb()",
"type": "string"
}
},
"required": [
"fg",
"bg"
],
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"contrast_ratio": {
"type": "number"
},
"passes": {
"type": "object"
},
"summary": {
"type": "string"
}
},
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}