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File Hash — Checksum Calculator & Verifier

Drop a file to get its SHA-256 (and more); paste the published hash to see match or mismatch instantly. Even multi-gigabyte ISOs are read in chunks on your own device — nothing is uploaded.

On-device・No upload

Your files and input are processed only inside your browser on this device and are never uploaded to our servers.

Drop files to hash (multiple, any size)

or

Files are not uploaded — hashing happens on this deviceAccepts: Any formatPaste (Ctrl+V) also works

Algorithms

All selected algorithms are computed together in a single read of each file.

The algorithm is detected from the length (32 = MD5, 40 = SHA-1, 64 = SHA-256 …). SRI values (sha384-…) work too.

Verify with a checksum file

Paste the contents of SHA256SUMS, *.sha256, *.md5 etc., or open the file (dropping it above works too). GNU and BSD formats are supported.

How to use

  1. Drop the files you want to check, or click “Choose files” (multiple allowed). Hashing starts right away.

  2. Pick more algorithms if needed — every selected algorithm is computed in a single read of each file.

  3. Paste the hash published by the source into “Expected hash” to see whether each file matches.

  4. If there is a checksum file such as SHA256SUMS or *.sha256, drop it with the files or paste it below to verify everything at once.

  5. Copy all results, save a CSV, or save a sha256sum-compatible SHA256SUMS file.

What it does

Multi-GB files without freezing

Files are read 8 MB at a time and hashed incrementally in a Web Worker, so memory stays flat and the page stays responsive even for huge files. Progress and speed are shown, and you can cancel at any time.

Several algorithms, one read

Choose any of MD5, SHA-1, SHA-256, SHA-384, SHA-512, SHA3-256, BLAKE3 and CRC32 — all of them are computed from a single pass over each file.

Paste-and-compare

The algorithm is detected from the hash length. Case, spaces, prefixes like “sha256:” and SRI values (sha384-…) are normalised. If the needed algorithm was not computed yet, one click adds it.

Checksum-file verification

Reads GNU (sha256sum) and BSD (SHA256 (name) = …) formats from SHA256SUMS, *.sha256, *.md5 and friends, matches entries to your files by name and lists OK, mismatch and missing.

Ready-to-use output

Save a checksum file that sha256sum -c can verify, or a UTF-8 CSV (with BOM) for spreadsheets.

Use cases

  • Confirm a downloaded OS image (ISO) or installer matches the publisher’s SHA-256
  • Check a file hash without remembering certutil or sha256sum commands
  • Create a SHA256SUMS list to ship alongside deliverables
  • Make sure files copied to a USB drive or the cloud are identical to the originals
  • Verify a whole release against its bundled SHA256SUMS in one go

Supported formats

Files

Any format (raw bytes are hashed)Multiple files (up to 500)No size limit (depends on your device)

Algorithms

MD5SHA-1SHA-256SHA-384SHA-512SHA3-256BLAKE3CRC32

Checksum files

SHA256SUMS / MD5SUMS etc.*.sha256 / *.sha1 / *.md5 / *.sha512GNU format (sha256sum)BSD format (shasum --tag)

Capability matrix

FeatureSupportNotes
Chunked hashing of large filesSupported8 MB chunks, constant memory
Multiple files and algorithms at onceSupportedUp to 500 files
Compare with an expected hash (auto-detect)Supported64 hex digits are checked against SHA-256, SHA3-256 and BLAKE3
Verify with a checksum fileSupportedGNU and BSD formats
Matching by folder pathPartialMatches by file name; identically named files in different folders may be ambiguous
Signature verification (GPG / minisign)Not supportedOnly hash equality is checked
Hashing files inside a ZIP individuallyNot supportedThe archive as a whole is hashed
Offline useSupportedWorks without a connection once loaded

Limits & notes

  • Up to 500 files per batch.
  • No file-size limit, but speed depends on your device and storage (roughly hundreds of MB/s for SHA-256).
  • Checksum files are auto-detected when they are 2 MB or smaller and named like SHA256SUMS or *.sha256.
  • A match cannot detect a tampered published value — always take the expected hash from the official HTTPS page.

Privacy & safety

Files are never uploaded: your browser reads them directly on your device. File names, contents and hashes are not sent, stored or included in analytics — safe for confidential data and large backups.

FAQ

Why does my hash not match?
Usually the download was incomplete, you are comparing against a different version, or the algorithm differs (e.g. a SHA-1 value against SHA-256). Download again and double-check the algorithm and file name on the publisher’s page.
Will I get the same value as certutil or shasum?
Yes. It is the same calculation as certutil -hashfile file SHA256 or shasum -a 256. certutil prints upper case, but comparisons here ignore case.
Can it handle multi-GB ISO files?
Yes. Files are hashed while being read 8 MB at a time, so memory use stays low. Time depends on your storage; a few GB on a typical SSD takes tens of seconds.
Should I check MD5 or SHA-256?
Use SHA-256 when both are published. MD5 can be deliberately forged, so it is not trustworthy for tamper detection, though it still catches accidental corruption.
Are my files uploaded?
No. The browser reads the files locally to compute the hashes; nothing leaves your device, and it keeps working offline once loaded.

Related tools

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Duplicate Files

Load a whole folder and see groups of files whose content is byte-for-byte identical, with the space they waste. Nothing is uploaded and nothing is deleted: save the keep/duplicate verdicts as CSV or JSON and clean up with your own file manager.

Disk Usage Analyzer

Load a folder and see where the space goes as a treemap. Click a rectangle to drill down, then export tables by extension, kind, largest files, old files and duplicate candidates to Excel or CSV. Neither file names nor contents leave your device.

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File Split & Join

Cut a file to a size you choose (around 18 MB suits a 25 MB mail limit), save it as name.ext.001, .002 … and put it back together on the same page. Multi-GB files are read in small pieces on your device, so memory stays flat. Missing or mixed-in parts are reported before joining, and a SHA-256 record confirms the result.

Archive Studio — ZIP, TAR & tar.gz Viewer, Extractor & Creator

Drop a ZIP, TAR, tar.gz or gz to list what is inside — including ZIPs made on Japanese Windows whose file names are normally garbled. Extract safely, re-create a ZIP with UTF-8 names, or build a ZIP / tar.gz from folders. Everything runs on your device.

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