File Hash Calculator (SHA-256, SHA-1, MD5)

Drop one or more files, get all the common cryptographic hashes calculated entirely in your browser. Compare against published checksums to verify downloads, audit binaries for tampering, or generate hashes for your own integrity-checking workflow. Files never leave your device.

How to use the File Hash Calculator (SHA-256, SHA-1, MD5)

Drop any file (or files). Each selected algorithm is computed; large files stream chunk-by-chunk so memory usage stays modest even for multi-GB downloads. The "Verify against" field lets you paste a known good checksum — match status updates as it computes.

About File Hash Calculator (SHA-256, SHA-1, MD5)

Cryptographic hashes are one-way digests that produce a fixed-size output from arbitrary input. Two practical uses: integrity verification (download a file, hash it, compare to the published hash, and you know the bytes match) and content addressing (use the hash as a stable identifier for content). SHA-256 is the modern default; SHA-512 is faster on 64-bit CPUs for very large files; SHA-1 and MD5 are legacy and not collision-resistant but still appear on older download mirrors.

This calculator uses the browser's native WebCrypto API for SHA-1 and SHA-256/384/512. MD5 is computed via a small JS implementation since WebCrypto deliberately omits it. Everything runs locally — the file content never travels over the network, so it's safe to hash sensitive binaries (signed app bundles, encrypted archives, internal release artifacts).

Common use cases

  • Download verification — confirm a Linux ISO, an installer, or a software release matches the publisher's checksum.
  • Content addressing — generate a stable identifier for a file you'll cache, dedupe, or compare against a reference set.
  • Forensics / change detection — record hashes for important files so you can detect tampering later.
  • Build artifact verification — confirm a CI-built binary matches one downloaded from your release server.

Frequently asked questions

How fast is it?
WebCrypto runs at near-native speed — typically 500MB/s for SHA-256 on modern hardware. A 1GB file hashes in 2-3 seconds.

Why is MD5 deprecated?
Practical collision attacks exist since 2004 — two different inputs can produce the same MD5 hash. For integrity against accidents (corruption during download) it's fine; for any security boundary, use SHA-256 or stronger.

Can I hash very large files?
The tool streams in 4MB chunks so memory usage stays low. Practical upper bound is browser file-handling limits — most browsers handle 10GB+ files comfortably.