Free tools for HTML and the web.
Everything runs in your browser, nothing is uploaded, no signup. And when your code looks right, every tool can publish it as a real live link in one click.
HTML viewer and tester
Paste HTML and see it render live in a sandboxed preview. Scripts and CSS run, so you test the real result before you share it.
Open the viewer → Clean upHTML formatter and beautifier
Turn messy or minified HTML into clean, indented code. Pick 2 spaces, 4 spaces, or tabs, then copy the result or publish it.
Open the formatter → ValidateJSON formatter and validator
Pretty-print or minify JSON, and find syntax errors with exact line and column numbers.
Open the formatter → CompressCSS minifier and beautifier
Shrink CSS for production or expand minified CSS into readable code, with the size saving shown.
Open the minifier → Un-minifyJavaScript formatter
Turn one-line minified JavaScript back into clean, indented, readable code.
Open the formatter →Have a page ready to go? Skip the tools and drop your HTML, PDF, or ZIP straight onto yapp.page. Live link in about two seconds, free, no signup.
Publish a page →Why these tools are free
yapp.page is the fastest way to put a page on the internet. These tools cover the small jobs around that: checking that your HTML works, and making it readable. They run entirely in your browser, so your code stays private, and each one ends with the same option: publish it as a live yourname.yapp.page link.
Built something with ChatGPT or Claude? Connect yapp.page once and your AI can publish for you mid-conversation. See how →