File Hash Generator
Hash text or files with SHA-1, SHA-256, or SHA-512 directly in your browser. Nothing is uploaded.
Pure browser JavaScript — uses the Web Crypto API (crypto.subtle).
How to use this tool
- Paste text or choose a file.
- Select the algorithm.
- Click Hash to see the hex digest.
Hash text or files with SHA-1, SHA-256, or SHA-512 directly in your browser. Nothing is uploaded.
How it works
The File Hash Generator computes a cryptographic hash (SHA-1, SHA-256, or SHA-512) for any text or file you provide. A hash is a fixed-length fingerprint: even a single changed character produces a completely different digest, making hashes ideal for verifying file integrity.
To verify a download, compute the SHA-256 hash of the file you received and compare it character-for-character against the checksum published by the software vendor. A match confirms the file was not corrupted or tampered with in transit.
All computation happens in your browser using the Web Crypto API. Your files and text are never transmitted to any server, so sensitive documents can be hashed safely.
SHA-256 is the most widely used algorithm today for general integrity checks. SHA-512 offers a larger digest and is preferred in high-security contexts. SHA-1 is provided for legacy compatibility but is no longer considered collision-resistant for security purposes.
Worked example
Verify an ISO download
- Download the ISO file and locate the official SHA-256 checksum on the vendor's website.
- Open the File Hash Generator and select the downloaded ISO via the file picker.
- Choose SHA-256 as the algorithm.
- Click Hash -- the digest appears within a few seconds.
- Compare each character of the result against the vendor's published checksum.
A 64-character hex string. If it matches the published value exactly, the file is authentic and intact.
Common mistakes to avoid
- Comparing hashes case-insensitively when one source uses lowercase hex and another uses uppercase -- both are equivalent, but a manual character-by-character comparison can be confused by mixed case.
- Hashing the compressed archive but comparing against the checksum of the extracted file -- make sure you hash the same artifact the vendor checksummed.
- Choosing SHA-1 for security verification -- use SHA-256 or SHA-512 instead.
Key terms
- Hash / digest
- A fixed-length string produced by a hash function that uniquely represents the input data. Any change to the input produces a different hash.
- SHA-256
- Secure Hash Algorithm 256-bit -- produces a 256-bit (32-byte, 64 hex character) digest. The current standard for most integrity checks.
- Checksum
- A hash value published alongside a file so recipients can confirm the file arrived without modification.
Frequently asked questions
- Is my file uploaded?
- No — hashing runs locally via the browser's built-in Web Crypto API (crypto.subtle). Nothing leaves your device.