voiddo colorcontrast vs WebAIM Contrast Checker
Both test WCAG AA and AAA color contrast ratios. This page compares privacy, features, input formats, and when each is the better choice for accessibility work.
voiddo colorcontrast — use when
- You want a native color picker — no hex memorization needed
- You're testing colors in RGB or HSL format from your design system
- You want to see how text actually renders at that contrast ratio
- You need to test several color combinations quickly using presets
- You're working offline or on a slow connection
WebAIM — use when
- You need WCAG 1.4.11 non-text contrast (UI components, icons)
- You're writing an accessibility audit report that cites a specific tool
- You need to share a URL with a specific color pair pre-filled
- Your org requires referencing a widely recognized authority tool
Feature comparison
| Feature | voiddo colorcontrast | WebAIM Contrast Checker |
|---|---|---|
| Install required | ✓ None — browser tab | ✓ None — browser tab |
| Server-side processing | ✓ None — 100% local JS | — Page loads from webaim.org |
| Works offline | ✓ Yes, after first load | — Requires connection |
| Native color picker | ✓ Yes — syncs with hex field | — No — hex input only |
| Input: Hex (#RRGGBB) | ✓ Yes | ✓ Yes |
| Input: RGB notation | ✓ Yes — rgb(R,G,B) | — No |
| Input: HSL notation | ✓ Yes — hsl(H,S%,L%) | — No |
| Contrast ratio | ✓ Live display | ✓ Display |
| WCAG AA normal text (≥4.5:1) | ✓ Pass/fail badge | ✓ Pass/fail |
| WCAG AA large text (≥3:1) | ✓ Pass/fail badge | ✓ Pass/fail |
| WCAG AAA normal text (≥7:1) | ✓ Pass/fail badge | ✓ Pass/fail |
| WCAG AAA large text (≥4.5:1) | ✓ Pass/fail badge | ✓ Pass/fail |
| WCAG 1.4.11 non-text contrast | — Not included | ✓ Dedicated panel |
| Live text preview | ✓ Normal, large, UI samples | — No preview |
| Swap colors button | ✓ One click | — No |
| Preset color combos | ✓ 6 common pairs | — No presets |
| URL sharing (pre-filled colors) | — No | ✓ Via URL params |
| Account required | ✓ No | ✓ No |
| Price | ✓ Free | ✓ Free |
| Luminance algorithm | WCAG 2.1 standard | WCAG 2.1 standard |
Frequently asked questions
Is the voiddo color contrast checker as accurate as WebAIM?
Yes. Both tools implement the identical WCAG 2.1 relative luminance formula: linearize each sRGB channel using the standard piecewise gamma, then apply the 0.2126R + 0.7152G + 0.0722B weighted sum. The contrast ratio is
(L1+0.05)/(L2+0.05). Results will match WebAIM to within floating-point rounding on any given hex pair.Does voiddo colorcontrast send my colors to a server?
No. voiddo colorcontrast runs the entire luminance computation in your browser using JavaScript — nothing is sent to voiddo's servers. For teams working with unreleased brand colors or sensitive design tokens, this means the colors never leave the browser tab.
What color formats does each tool accept?
voiddo colorcontrast accepts hex (
#RRGGBB or shorthand #RGB), RGB notation (rgb(255,255,255)), and HSL notation (hsl(210,100%,50%)). It also includes a native color picker that syncs bidirectionally with the hex field. WebAIM Contrast Checker accepts hex values only and does not include a color picker.Does WebAIM contrast checker work offline?
No. WebAIM's contrast checker requires a network connection to load the page from webaim.org on each visit. voiddo colorcontrast works fully offline after the first page load because all computation uses local JavaScript with no runtime server calls.
Which contrast checker should I use for official accessibility audits?
For formal WCAG audits and reports that cite a specific tool, WebAIM's contrast checker (webaim.org/resources/contrastchecker/) is the most widely recognized reference and is frequently cited in professional audit documents. For everyday design work — iterating on color palettes, comparing multiple combinations, or verifying ratios quickly — voiddo colorcontrast is faster thanks to its native color picker, live text preview, and preset combos.
Does WebAIM check WCAG 1.4.11 non-text contrast?
Yes. WebAIM's contrast checker includes a dedicated WCAG 1.4.11 Non-Text Contrast section that tests UI components and graphical objects at the ≥3:1 minimum. voiddo colorcontrast focuses on text contrast (WCAG 1.4.3 and 1.4.6) and does not include a separate non-text contrast panel. If you need to test icon or border contrast, WebAIM is the right tool for that specific check.
Try voiddo colorcontrast — free, no account
Native color picker · Hex + RGB + HSL · Live text preview · Works offline
Open colorcontrast → browse all 44 comparisons →