WCAG Color Contrast Checker
WCAG Color Contrast Checker helps you preflight measurable file, dimension, duration, text, or upload fields before using an official or platform workflow.
The checker returns pass, warn, and fail items, a copy-all result, source references, and local repair links where a TextFaker tool can help.
Choose a file
The browser fills file name, size, and available media dimensions locally. Add missing fields on the right.
Preflight fields
References
- Open Graph Protocol
Official Open Graph protocol reference for social preview metadata.
- Google Search Central Sitemaps
Official Google guidance for sitemap index and sitemap size limits.
- W3C WCAG Contrast Minimum
Official W3C understanding document for WCAG color contrast minimums.
Repair links
WCAG Color Contrast Checker Guide
What this preflight checks
WCAG Color Contrast Checker is a base verification utility for measurable fields, not a human review or official approval service. It reads local file metadata where the browser exposes it and accepts manual values for fields that cannot be safely inferred in the browser.
Common checks inspect pasted markup, metadata, manifest text, robots text, sitemap snippets, or measured contrast values.
- Contrast ratio: Measured contrast ratio should be at least 4.5:1.
- Color values: Enter color values or notes with a measured contrast ratio.
- Text size: Text input should be 20,000 characters or fewer.
- File name length: File name should be 120 characters or fewer.
How to read the result
A pass item means the provided value met the local rule. A warn item means the checker needs more source data, such as page count, DPI, duration, or pasted markup. A fail item names a measurable value that is outside the configured preflight rule.
Use the copy-all button to save the full report with labels, input values, checks, and reference names. That makes it easier to compare fixes before uploading again.
- Pass: the provided measurable value fits the configured rule.
- Warn: the checker needs more local data before it can decide.
- Fail: fix the file, dimensions, duration, text, or naming issue before submission.
Sources and variants
WCAG Color Contrast Checker stores official or standards references with the base checker. Country, region, or platform variants should be added as data presets only when their source URL, last-verified date, and allowed jurisdiction are present.
This base checker does not publish country variants unless a future preset includes an approved jurisdiction and source-backed rules.
- Source policy: official-required.
- Base variant count planned: 0.
- Demand proof URLs stored: 2.