Sourwood Labs LLC

Generate SHA-256, MD5, SHA-1/384/512 & CRC32 hashes for text or a file, then verify a checksum, instantly and on-device.

SHA-256 generator, MD5 checksum & file hash, without uploading anything A hash generator and checksum tool for text and files: paste text or drop a file and get its hash instantly, right in the popup. You get SHA-256, MD5, SHA-1, SHA-384, SHA-512, and CRC32, each as lowercase hex with one-click copy. Then paste an expected hash and verify a checksum: the tool tells you MATCH or NO MATCH, the fast way to verify a download, an installer, or a backup. PRIVATE BY DESIGN: WHY THIS MATTERS HERE You hash a file precisely because it matters: a download you are verifying, a credential, a secret, a private document. Uploading that file to a random online hash generator defeats the entire point. This extension is a paste/drop-mode popup. The text or file you hash never leaves your browser. It never reads the active tab or any page content, requests no host permissions, downloads nothing, and injects no scripts. Hashing runs entirely on your device using the browser's built-in WebCrypto for the SHA family plus small, bundled, first-party MD5 and CRC32 code (no CDN, no remote code, no eval). This extension collects no data of any kind: no analytics, no tracking, no telemetry, and no account is ever required to hash text or a file. The only network traffic it ever makes is a purchase-verification check with ExtensionPay if you choose to upgrade. WHAT IT DOES (FREE) - HASH TEXT: hashed as its UTF-8 bytes (so "café" is encoded correctly, exactly like every standard tool), with the encoding stated on screen. - HASH A FILE: drop a file or pick one; it is hashed as its raw bytes. Large files are streamed in chunks (MD5/CRC32) or read directly as bytes (SHA), never loaded as a giant text string. - SIX ALGORITHMS: MD5, SHA-1, SHA-256, SHA-384, SHA-512, and CRC32, each shown as lowercase hex with a copy button. - VERIFY A DOWNLOAD: paste the published/expected hash and get an instant MATCH / NO MATCH. The compare is case-insensitive and ignores whitespace, and it tells you which algorithm the pasted hash actually is. HOW TO USE 1. Paste text, or drop a file (or click to pick one), into the popup. 2. Read the hash for all six algorithms at once (MD5, SHA-1, SHA-256, SHA-384, SHA-512, CRC32), each with its own copy button. 3. To verify a download, installer, or backup: paste the published/expected hash into the compare field and read MATCH or NO MATCH. PRACTICAL USE A downloaded installer publishes a SHA-256 checksum on its download page: drop the installer file in, paste that checksum into the compare field, and get an instant MATCH / NO MATCH. No separate app, no upload, nothing to install. BUILT TO GET THE HARD PARTS RIGHT: CORRECTNESS IS EVERYTHING A hash tool that shows the wrong digest is worse than useless: the output looks valid and a corrupted or tampered file could pass verification. So every algorithm is checked against its PUBLISHED known-answer test vectors (NIST for the SHA family, RFC 1321 for MD5, the standard CRC-32 check value) for the empty string, "abc", and the classic pangram; the constants come from the specs, not from our own code. Text is always hashed as UTF-8 bytes, and a file is hashed as its exact raw bytes. HONEST ABOUT SECURITY (NO FALSE CONFIDENCE) - SHA-256, SHA-384, and SHA-512 are collision-resistant and fine for tamper-evidence today. - MD5 and SHA-1 are cryptographically broken (practical collisions). They are great for matching a legacy or published checksum, but NOT for proving a file has not been tampered with. The UI labels them "not secure". - CRC32 is a CHECKSUM, not a cryptographic hash. It detects accidental corruption (a bad download, a flipped bit), NOT deliberate tampering. The UI labels it "checksum". PREMIUM ($5 one-time) - Batch multi-file hashing: hash a whole set of dropped files at once (free hashes one file at a time). - HMAC mode (keyed hash): HMAC-MD5 / SHA-1 / SHA-256 / SHA-384 / SHA-512 over a secret key and message, verified against the RFC 2202 / RFC 4231 test vectors. - Saved compare-lists: save a named expected-hash manifest (file label + algorithm + expected hash) and check a set of files against it. Stored only on your device (labels and expected hashes only, never any file bytes). No subscription, no account required; pay once, keep the features.