check_contrast

shallow

dev.craftery/tools · Verify this server

Compute the exact WCAG 2.1 contrast ratio between a foreground and background color (relative-luminance formula) and report AA / AAA pass-fail for normal text (4.5 / 7), large text (3 / 4.5), and UI components (3). Use this instead of estimating contrast — the luminance math is precise here.

100.0/100

1 trials · measured 50 days ago

check_contrast scores 100.0/100 on Vouch's measured behaviour index, from 1 real invocation trials against dev.craftery/tools, measured 31 Aug 2026 under methodology v0.2.0. Every measured component scored 100.

Component breakdown

ComponentWeightValue
Reliability35%not applicable
Schema integrity25%100.0
Failure behaviour15%not applicable
Latency15%not applicable
Concurrency10%not applicable

Tool details

Transport
remote
Credential class
self-provisionable
Input schema
not declared
Output schema
not declared
Side-effect classification
unclassified

Score history

DayScoreTierMethodology
2026-08-31100.0shallowv0.2.0

Probe evidence

ProbeOutcomes
schema_integritypass: 1

Raw request/response logs are not archived yet — the outcome counts above are drawn directly from every recorded trial.

Embed this score

Available for every tool, scored or not — not a verification perk. Always links back to this page.

Vouch score: check_contrast
[![Vouch score](https://vouch.tools/api/tools/e9ad4780-0170-4600-a0d6-3e71c4623279/badge.svg)](https://vouch.tools/tools/e9ad4780-0170-4600-a0d6-3e71c4623279)
check_contrast — Vouch