Hash & Encoder Tools

A developer's Swiss-army knife for hashing & encoding

Every day, developers need to compute a hash, encode a Base64 string, URL-encode a value, or unescape HTML entities. The usual workflow involves jumping between several scattered sites (each plastered with ads). This page brings the most common 15 operations into a single, consistent interface.

Hachages (MD5, famille SHA)

We compute MD5, SHA-1, SHA-256, SHA-384 and SHA-512. SHA hashes use the browser's native Web Crypto API — fast and standardized. MD5 is shipped as a small in-house implementation since Web Crypto deliberately omits it (cryptographically broken since 2005, but still useful for file checksums and content addressing).

File hashing: drop any file into the input box, or click "Drop or pick a file". We read it as raw bytes and hash directly — the result will match exactly what md5sum, sha256sum and the corresponding macOS / Windows tools produce.

Base64 (compatible UTF-8)

JavaScript's built-in btoa() throws on any Unicode character above U+00FF — which means it fails on accents, emojis, kanji, anything outside Latin-1. Our encoder round-trips through a UTF-8 byte buffer, so it handles any Unicode correctly. Decoding also tolerates whitespace and the URL-safe variant (- instead of +, _ instead of /).

Encodage URL

Uses encodeURIComponent, which is the right choice for embedding values in URL path segments or query parameters. Spaces become %20, ampersands become %26, etc.

Entités HTML

Escape converts the 5 dangerous characters (&, <, >, ", ') to their entity form — handy for sanitizing user input before inserting into HTML. Unescape handles named entities (©, — …), numeric (A) and hexadecimal (👋), including non-BMP Unicode like emojis.

Hex & Binary

Converts text to a hexadecimal or binary representation of its UTF-8 bytes, and back. The decoders are forgiving — they accept spaces, line breaks and 0x prefixes for hex.

Confidentialité

Nothing is ever uploaded. Hashes, encodings and file reading all happen locally. We don't store anything, we don't log anything, we don't analyze anything — there isn't even a server component that could.

Cas d'utilisation courants

• Verify a download matches its published sha256 checksum.
• Decode a Base64 string from a JWT, email header or config file.
• URL-encode a query value to test a problematic redirect.
• Strip HTML entities from text scraped from a webpage.
• Generate a deterministic content hash for caching or deduplication.