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About CSS Valid
When you need developer and design work done in seconds, CSS Valid delivers a clean, focused interface without the friction of a generic tool. Processing runs locally in your browser using modern Web APIs. Nothing is uploaded, nothing is logged, and there is no quota to worry about for casual use. It pairs naturally with the other developer utilities here when you need to chain a quick workflow.
When you'd reach for CSS Valid
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 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 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'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 CSS Valid
- Do I need to create an account to use CSS Valid?
- No. CSS Valid works without any signup. We only ask for an email if you decide to subscribe to a paid plan.
- Will CSS Valid change my original file?
- Never. CSS Valid only reads your input file and produces a new output file.
- Are my files uploaded to a server when I use CSS Valid?
- CSS Valid processes everything in your browser using local APIs. Your files never leave your device.
- What browsers does CSS Valid support?
- Every modern browser released in the last three years: Chrome, Firefox, Safari, Edge, Brave, Opera.
- Is CSS Valid really free?
- Yes — CSS Valid is free for unlimited personal use, with no account required and no watermark on the output.