How to use the File Hash Calculator
1. Drag and drop any file onto the area below, or click to browse. The file never leaves your browser.
2. SHA-256, SHA-512, SHA-1, and MD5 hashes are computed instantly using WebCrypto.
3. Optionally paste a known hash in the Verify box to check file integrity.
What is it?
A file hash (or checksum) is a fixed-length fingerprint of a file's contents. Even a single changed byte produces a completely different hash. This makes hashes useful for verifying file integrity after download, detecting tampering, and deduplication.
SHA-256 is the recommended algorithm for integrity checking. MD5 and SHA-1 are provided for compatibility with older systems — they are no longer considered secure for cryptographic purposes.
Benefits
Verify data integrity instantly
Hash comparison confirms whether a file, API response, or downloaded binary has been altered in transit or at rest — without storing the original content.
Authenticate requests and webhooks
HMAC signatures prove a request came from a trusted source and was not modified in transit — the mechanism behind Stripe, GitHub, and AWS webhook security.
Protect sensitive data at rest
AES-256 encryption makes stored content unreadable to anyone without the key — even if your database, S3 bucket, or file system is fully compromised.
Generate credentials that meet security standards
Cryptographically random output from the Web Crypto API satisfies NIST entropy requirements — unlike predictable Math.random()-based alternatives.
Frequently asked questions
Does the file get uploaded anywhere?
No. The file is read entirely in your browser using the FileReader API. Nothing is transmitted to any server.
How do I verify a downloaded file?
The software publisher usually provides a SHA-256 checksum alongside the download. Drag the file here, then paste the published hash in the Verify box — a green match means the file is genuine and unmodified.