Sample Text Preview
This shows how text looks with these colors
Get a free API key + new tools as they ship
100 calls/day, no card, no spam. Built by one person, in public.
About Contrast Ratio
Working with developer and design work no longer requires installing heavy desktop software — Contrast Ratio runs entirely in your browser, instantly. Built to be the kind of tool you bookmark and use weekly: no surprises between visits, no degraded free tier, and a UI that gets out of the way. It pairs naturally with the other developer utilities here when you need to chain a quick workflow.
When you'd reach for Contrast Ratio
You're on a public or shared machine and don't want to leave traces of what you're working on.
Travelers, contractors, anyone working from a friend's computer.
Nothing is uploaded, nothing persists if you're not signed in.
You're hitting the daily limit of a paid SaaS and need a backup option for a single quick job.
Marketers and ops people whose primary tool is metered.
Stay productive without burning credits.
You need to handle a one-off task right before a meeting and don't have time to install anything.
Anyone working remotely on a borrowed or restricted machine.
Open the page, get the result, paste it into your doc — under a minute.
You're cleaning up a folder of files that accumulated over a project and need to standardize them.
Designers, writers, and developers wrapping up deliverables.
Drop each file in, copy the output, move on.
Frequently asked about Contrast Ratio
- What browsers does Contrast Ratio support?
- Every modern browser released in the last three years: Chrome, Firefox, Safari, Edge, Brave, Opera.
- Can I use Contrast Ratio commercially?
- Yes. The output of Contrast Ratio belongs entirely to you, with no licensing restrictions.
- Will Contrast Ratio change my original file?
- Never. Contrast Ratio only reads your input file and produces a new output file.
- Are my files uploaded to a server when I use Contrast Ratio?
- Contrast Ratio processes everything in your browser using local APIs. Your files never leave your device.
- Do I need to create an account to use Contrast Ratio?
- No. Contrast Ratio works without any signup. We only ask for an email if you decide to subscribe to a paid plan.