Developer tools
JSON, Base64, hashes, UUIDs and URL encoding.
Nothing is uploaded. This tool runs entirely inside your browser tab. Your files and figures stay on your device - we never receive them, so we cannot read, store or lose them.
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JSON formatter
Format, validate and minify JSON with precise error locations, optional key sorting and a structural summary of what the document contains.
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Base64 encode/decode
Encode and decode Base64 with full Unicode support, including a URL-safe alphabet, and encode any file to Base64 without uploading it.
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UUID generator
Generate RFC-compliant UUIDs in bulk - random v4 or time-sortable v7 - with formatting options and no server involvement.
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Hash generator
Generate MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hashes from text or any file, computed entirely on your device.
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URL encoder/decoder
Percent-encode and decode URLs and query parameters, with a breakdown of any URL into its origin, path and decoded parameters.
Safe for payloads you should not paste elsewhere
Developers routinely paste API responses, JWTs, config fragments and production data into online formatters. Most of those tools are server-side, which means that payload has been transmitted and quite possibly logged.
Everything here runs in your browser. That does not make a browser tab a secure enclave - extensions and screen sharing are still real - but it does remove the network hop entirely, which is the part you cannot audit.
The tools
- JSON formatter - beautify, minify and validate with the exact error line and column, plus a structural summary and key sorting.
- Base64 encode and decode - correct UTF-8 handling for every language, a URL-safe alphabet option, and file encoding.
- Hash generator - MD5, SHA-1, SHA-256, SHA-384 and SHA-512 for text or any file, for verifying downloads and checksums.
- UUID generator - random v4 and time-sortable v7, in bulk, with formatting options.
- URL encoder and decoder - percent encoding in both component and full-URL modes, plus a query parameter breakdown.
Correctness details that bite
Several of these tools exist because the naive implementation is subtly wrong. Base64 through
btoa corrupts anything outside Latin-1. JSON numbers beyond 253 lose
precision silently, which breaks 64-bit IDs from APIs. Percent-encoding a whole URL with
encodeURIComponent destroys it. Each tool documents the trap it avoids.