Software · Photo & graphics

Ratio

Validate color contrast.

Completely free
Linux
Open source

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Geographic availability: No geographic restriction found in our sources; availability is not checked country by country.

Technical details

Pricing: Completely freeconfirmed by Flathub
License: GPL-3.0+ — Open source (copyleft)confirmed by Flathub
Open source: Yes
Commercial use: Yesconfirmed by Official plan pages (pricing, licence, terms), Flathub
Account required: not documented
Credit card required: Noconfirmed by Flathub
Watermark: not documented
Ads: not documented
Platforms: LinuxEstablished by Linux: Flathub
Publisher: Mark Wyner
Latest version: 1.0.6 (6 October 2026)
Latest activity: 7 October 2026
Source code: codeberg.org/markwyner/ratio-for-linux

At a glance

Ratio is completely free: it is open source software, and every feature is available without paying or subscribing.

Its licence (GPL-3.0+) is a copyleft open source licence: you may use, study, modify and redistribute it, including commercially; modified versions must keep the same licence.

Strengths

Open source code
Commercial use allowed

About

Ratio uses WCAG algorithms to validate color contrast for accessibility. Specifically for the WCAG Success criteria 1.4.3 (text), 1.4.11 (non-text elements), and 2.4.13 (focus appearance). I made it for myself, but it is also my gift to you. (There’s also a macOS version available.)

Description from Flathub — AppStream (Flathub)

Sources and checks

Facts collected from Official plan pages (pricing, licence, terms) (commercial use) — 10 November 2026
Facts collected from Flathub (credit card, source code, publisher, licence, free status, platforms, commercial use, version) — 10 November 2026
Last technical check: 8 November 2026
Description from Flathub — AppStream (Flathub)

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