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 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.

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, each with its own copy button.

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

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

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

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.

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.

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.

Convert between scientific notation and full numbers as you type. Reads 1.23e5, 1.23 × 10^5 and plain numbers, shows the value written out, in normalized scientific notation and in engineering notation, and can round to any number of significant digits.

Sort the lines of a text alphabetically, naturally, by length, by numeric value or shuffled. Reverse the order with a switch, and optionally trim lines, drop blank lines and remove duplicates in the same pass.

Convert a color between HEX, RGB, HSL, HSV, HWB, CMYK, OKLCH and OKLAB. Type into any field and the others update as you go, or pick the color visually. Reads CSS color syntax and keeps alpha where the format supports it.

Check two colors against the WCAG contrast rules. Type or pick a text and a background color, read the contrast ratio, see which AA and AAA checks pass, preview real text at the sizes WCAG distinguishes, and get suggested fixes when a check fails.

Create a QR code for text, a link, an email, a phone number, an SMS, Wi-Fi access or a contact card. Set the error correction level, size, margin and colors, then download it as PNG or SVG or copy it straight to the clipboard.

Paste a cron expression and get a plain English explanation, a field by field breakdown and the next times it would run, in your local timezone or UTC. Reads five field crontab syntax, six fields with seconds, names like MON and macros like @daily.

Work out an IPv4 or IPv6 network from an address with a prefix or netmask: network and broadcast addresses, usable host range, subnet mask, wildcard mask and address type. Adjust the prefix with a slider, read the binary breakdown, and split the network into smaller subnets.

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.

Encode text for use in URLs or decode percent-escaped strings back to readable text. Choose component, full-URL or form encoding, unwrap double-encoded strings, and break a URL into its parts with every query parameter decoded.

Convert Unix timestamps in seconds, milliseconds, microseconds or nanoseconds to readable dates in your local time, UTC or any timezone, and turn any date back into a timestamp. Shows the live current timestamp and relative time.

Escape text into HTML entities or decode entities back to plain text. Choose named or numeric entities, escape only the unsafe characters or everything outside ASCII, and read the result live.

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.

Compress text or a file with gzip, deflate, brotli or Zstandard and see the size before and after, the compression ratio and how long it took. One click tries every method and recommends the smallest result.

Decompress gzip, deflate, brotli or Zstandard data from a file or pasted Base64 and read the result as text or download it. Detects the format from the magic bytes where possible, with a manual override.

About the Checksum Validator

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.

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.

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.

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.

See what your clipboard really holds. One press lists every format on it, from plain text and HTML to Excel tables and images, each with its type, size and a preview. Pasting works too, and can reveal even more formats.

Check two colors against the WCAG contrast rules. Type or pick a text and a background color, read the contrast ratio, see which AA and AAA checks pass, preview real text at the sizes WCAG distinguishes, and get suggested fixes when a check fails.

Convert a color between HEX, RGB, HSL, HSV, HWB, CMYK, OKLCH and OKLAB. Type into any field and the others update as you go, or pick the color visually. Reads CSS color syntax and keeps alpha where the format supports it.