Nearby tools from the catalog that fit the same job or workflow.
Check OG image fit
Preview one Open Graph image locally and check the practical share-card fit.
Solve aspect ratios
Reduce aspect ratios, solve missing dimensions, and check common layout presets.
Check canonical tags
Check canonical tags from pasted HTML or head markup locally.
Convert CSS color formats
Convert one color between HEX, RGB, RGBA, HSL, and HSLA with a live swatch.
Check hreflang tags
Inspect pasted hreflang tags locally and flag duplicates or suspicious codes.
Check practical HTML issues
Run a practical HTML checker on pasted markup and surface common SEO/content issues locally.
Everyone can see the current score. Signed-in users can leave a 1 to 5 star rating, and any written review goes only to review@cleanor.app.
No ratings yet. Be the first to leave one.
Sign in to leave a public score from 1 to 5 stars. Optional written feedback is private and emailed only to review@cleanor.app.
This block mirrors the system review flow: score first, then an optional private note.
A quick way to understand who this helps, what it solves, and where it connects next.
Designers and developers checking WCAG color contrast.
Using the color contrast checker without installing anything or signing up.
Capture color-contrast-checker intent with a fast, browser-side tool that runs 100% locally.
Cleanor Labs
These sections explain the job in plain language and set expectations for what the tool should do well.
The color contrast checker measures the WCAG contrast ratio between a foreground (text) color and a background color, then tells you at a glance whether the pair meets AA (4.5:1 for normal text, 3:1 for large text) and AAA (7:1 and 4.5:1). Ratios use the official WCAG relative-luminance formula, and a live preview renders real sample text on your chosen background so you can judge readability, not just numbers. Everything runs locally in your browser, so nothing you type is ever uploaded.
Short answers for the questions people usually have before trying a utility like this.
WCAG AA requires 4.5:1 for normal text and 3:1 for large text (18pt, or 14pt bold). AAA is stricter: 7:1 for normal text and 4.5:1 for large text. This tool shows all four results at once.
It uses the official WCAG relative-luminance formula for each color, then divides the lighter luminance plus 0.05 by the darker luminance plus 0.05, giving a value from 1:1 to 21:1.
No. All color parsing and contrast math run entirely in your browser. No colors, values, or results are sent to any server.
Every tool on Cleanor is free with no sign-up, no credits, and no limits. Files are processed privately in your browser. Looking for on-device phone cleanup and Premium features? That lives in the Cleanor app.
Check any foreground and background pair against WCAG AA and AAA, live in your browser.
Large sample text
The quick brown fox jumps over the lazy dog. Normal body copy at this size needs a 4.5:1 ratio to pass WCAG AA.
17.40:1
Computed locally. Large text = 18pt bold or 24pt.