Skip to content
Marvin's Toolbox.

Search tools

Type to filter all tools

Checksum Validator

Verify a checksum online: drop a file, paste the expected checksum and see instantly whether they match. The hash type is detected from the checksum itself, covering MD5, SHA-1, SHA-256, SHA-512, BLAKE3, CRC-32 and more, and sha256sum lines or whole checksum files can be pasted as-is.

Everything runs locally in your browser. Your data never leaves your device.

File

Drop the file to verify

Any file type. Large files are hashed in chunks.

Expected checksum

A bare digest, a sha256sum line, a BSD-style line or a whole checksum file all work, in hex or Base64. The algorithm is detected automatically.

Result

Drop a file and paste the checksum that came with it. The verdict appears here.

Next steps

Send this tool's output straight into another tool.

Hash Generator

Hash text or a file with MD5, SHA-1, SHA-256, SHA-512, SHA-3, BLAKE2, BLAKE3, CRC32 and more, all computed live as you type. Compare against an expected checksum and copy any digest.

devsecurity

Text Case Converter

Convert text into every case at once: title case in the APA, AP, Chicago, MLA, Bluebook, AMA and NYT styles, sentence case, upper, lower, camelCase, snake_case, kebab-case and more.

textconverter

Word & Character Counter

Count words, characters, sentences, paragraphs, lines and more as you type, with estimated reading and speaking time.

text

Dedupe Lines

Remove duplicate lines from a list or text, keeping the first occurrence. Optionally ignore case and whitespace, or drop blank lines too.

textdev

Find and Replace

Replace text in two modes: plain find and replace all, or regular expressions with flag controls and capture group references like $1.

textdev

Text Diff

Compare two texts and see every added, removed and changed line highlighted, side by side or inline, with the changed words marked within each line. Ignore case, whitespace or blank lines, read a summary of how much changed, and export the result as a unified diff.

textdev

UUID Decoder

Paste a UUID to see what it carries: version, variant, and for time-based versions the exact timestamp, clock sequence and node. Also shows the raw bytes, the 128-bit integer and the URN form.

devuuid

Base64 Encoder & Decoder

Decode Base64 to text or encode text to Base64. Paste into the top box, read the result below, and flip the direction with one click. Handles Unicode correctly, reads URL-safe Base64, and shows binary payloads as a hex dump you can download.

devconvertertext

Number Base Converter

Convert numbers between binary, octal, decimal, hexadecimal and any base up to 36. Type into any field and the others update as you go. Handles huge integers without losing precision and accepts 0x, 0b and 0o prefixes.

devconvertercalculator

About the Checksum Validator Tool

This tool verifies a file against its checksum online. Drop the file in, paste the checksum that came with it, and you get a clear match or no match verdict. The hash type is detected from the checksum itself, so you don't need to know if the digest in front of you is MD5, SHA-1, SHA-256 or something else.

More than a bare digest works. Paste a sha256sum output line, a BSD-style SHA256 (file) = … line, a sha256:… prefixed digest, a Base64 digest or the entire contents of a checksum file. When a checksum file lists several files, the line that names your file is checked first.

What you can do

  • Verify a downloaded file against its published SHA-256 or MD5 checksum.
  • Check an ISO image, installer or firmware download before using it.
  • Detect the hash algorithm from the checksum automatically.
  • Paste a whole SHASUMS or MD5SUMS file and verify against the right line.
  • Verify checksums written as hex or Base64, including sha256sum and BSD formats.

How to use the Checksum Validator

  1. 1Drop the file you want to verify into the dropzone, or pick it with a click.
  2. 2Paste the expected checksum. A bare digest, a sha256sum line or a whole checksum file all work.
  3. 3The likely algorithm is detected and the file is hashed in a single pass.
  4. 4Read the verdict. Green means the file matches the checksum byte for byte.

How the algorithm is detected

Checksums often carry their algorithm with them. A BSD-style line names it outright, and prefixes like sha256: do too. Without a name, the digest length narrows it down: 32 hex characters point to MD5, 40 to SHA-1, 64 to SHA-256 and 128 to SHA-512. Several algorithms share a length, so every algorithm of that size is checked in a single pass over the file, and the verdict names the one that matched.

Only when nothing can be detected does the tool fall back to checking every supported algorithm. That still needs just one read of the file, so even the fallback stays fast.

When the checksum does not match

A red verdict means the file on your disk is not the file the checksum describes. For a fresh download, the usual causes are an interrupted or corrupted transfer, a mirror serving a different build, or a checksum copied for the wrong file or version. Download the file again, make sure the checksum belongs to exactly that version, and re-check.

A mismatch can also mean the file was tampered with. If a download from an unofficial mirror keeps failing verification, get it from the official source instead. The computed digests are shown next to the expected value, so you can see exactly how far off the result is.

Verifying and generating in one place

This tool answers one question: does the file match the checksum. To compute digests yourself, compare several algorithms side by side or generate an HMAC, use the Hash Generator. It shares the same hashing engine, streams large files in chunks and covers more than twenty algorithms.

Credits

Open source does the heavy lifting in this tool. Thank you to:

  • hash-wasm

    Hand-tuned WebAssembly implementations of MD5, SHA, BLAKE, bcrypt, Argon2 and many more.

Everything this site builds on is listed on the credits page.

Related tools

Bcrypt & Argon2 Generator

Hash a password with bcrypt or Argon2 and verify a password against an existing hash. Tune the cost factor, memory, iterations and parallelism, see how long the hash takes, and read the parsed parts of any hash you paste.

securitydev

Email Header Analyzer

Paste raw email headers to trace the Received chain hop by hop with per-hop delays, read the SPF, DKIM and DMARC results, and see every header explained. Helps you spot spoofing and find where a slow email got stuck.

devsecurity

Hash Generator

Hash text or a file with MD5, SHA-1, SHA-256, SHA-512, SHA-3, BLAKE2, BLAKE3, CRC32 and more, all computed live as you type. Compare against an expected checksum and copy any digest.

devsecurity

Invisible Character Revealer

Reveal the characters you can't see in a text: zero-width spaces, non-breaking spaces, bidi marks, control characters and CRLF versus LF line endings. Inspect every occurrence and clean them out with a click.

textdevsecurity

JWT Decoder

Paste a JSON Web Token to see its header and payload as formatted JSON, with the token color coded so each part maps to its output. Explains the registered claims, shows expiry as readable dates, flags expired tokens and can verify the signature with a secret or public key.

devsecurity

JWT Encoder

Build and sign a JSON Web Token from a header and payload. Supports the HMAC, RSA, ECDSA and EdDSA algorithms real systems use, fills in standard claims like expiry for you, and shows the signed token ready to copy.

devsecurity