Free browser tools that run locally

Convert, decode, format, and inspect common web data without uploading your files. CleanWebTools is built to do one task well per page, with a privacy-first workflow that keeps your input in the browser.

No signupStatic siteLocal tool input
cleanwebtools.com/tools/json-formatter
{"tool":"local","upload":false,"format":"json"}
{ "tool": "local", "upload": false, "format": "json" }

Built for real debugging work

CleanWebTools is for the small tasks that interrupt real work: checking a JWT claim, formatting a suspicious API response, decoding an embedded image, or confirming whether a timestamp is seconds or milliseconds. The pages stay narrow so the answer is easy to verify.

The guides document the edge cases behind those tools, including base64url alphabets, Unicode normalization, Markdown sanitization, token storage, and password hashing mistakes. When a claim depends on a standard or runtime behavior, the relevant guide links to the source or describes the test used to check it.