What is a checksum?+
A checksum is a short, fixed-size value computed from the contents of a file. Because it depends on every byte, even a tiny change produces a completely different checksum. Comparing a file’s checksum against a trusted value confirms the file is unchanged.
What is a file checksum validator?+
It is a tool that computes a file’s checksum (hash) and compares it against an expected value to verify the file’s integrity and authenticity. This validator generates MD5, SHA-1, SHA-2, SHA-3, BLAKE2, RIPEMD-160, Whirlpool and CRC checksums and validates them — all locally in your browser.
Why verify file integrity?+
To make sure a file wasn’t corrupted in transit or tampered with by an attacker. Verifying integrity protects you from broken installers, bit-rot, malicious download mirrors and supply-chain attacks. It is one of the simplest, highest-value security habits.
What is SHA-256?+
SHA-256 is a cryptographic hash function from the SHA-2 family that produces a 256-bit (64 hex character) digest. It has no known practical collisions and is the modern standard for verifying downloads, signing software and securing blockchains.
Is MD5 secure?+
No. MD5 has been cryptographically broken since the mid-2000s — attackers can deliberately create two different files with the same MD5 hash. It is fine for detecting accidental corruption but must not be relied on for security. Use SHA-256 or stronger to detect tampering.
Is SHA-1 secure?+
No. SHA-1 was practically broken by the 2017 “SHAttered” collision attack and is deprecated for security uses. Like MD5, treat it as an accidental-corruption check only and migrate to SHA-256, SHA-3 or BLAKE2.
What causes a checksum mismatch?+
A mismatch means the file you have differs from the original. Common causes are an incomplete or corrupted download, a different file version, the wrong algorithm being compared, transmission errors — or, more seriously, deliberate tampering. Re-download from the official source and verify again.
Can file corruption be detected?+
Yes — that is exactly what checksums are for. Any change to the file, even a single bit, changes its checksum, so comparing against a known-good value reliably detects corruption. Cryptographic hashes additionally detect intentional modification.
How do software vendors provide checksums?+
Vendors publish the expected hash (often SHA-256 or SHA-512) on their official, HTTPS-secured download or release page, sometimes in a SHA256SUMS file, and frequently alongside a GPG signature so you can verify the checksum file itself hasn’t been altered.
What is digital fingerprinting?+
A digital fingerprint is a short, unique identifier derived from a file’s cryptographic hash (and sometimes its metadata). It lets you reference, track, deduplicate or verify a file’s identity without comparing the whole file.
What is file tampering?+
Tampering is unauthorized modification of a file — for example, inserting malware into an installer. Cryptographic checksums detect tampering because any change produces a different hash that won’t match the publisher’s value.
What is checksum verification?+
Checksum verification is the process of recomputing a file’s hash and comparing it to a trusted expected value. If they match, the file is intact and authentic; if not, it has changed. This tool automates the computing and comparison.
Which checksum algorithm should I use?+
For verifying downloads and any security purpose, use SHA-256 (the default), SHA-512, a SHA-3 variant or BLAKE2. Use CRC32 only for fast accidental-corruption checks. Avoid relying on MD5 or SHA-1 for security.
What is the difference between MD5 and SHA-256?+
MD5 is a 128-bit, broken hash useful only for accidental-corruption checks. SHA-256 is a 256-bit, collision-resistant hash suitable for security and the standard for verifying downloads. Prefer SHA-256 whenever it is offered.
What is the difference between SHA-256 and SHA-512?+
Both are SHA-2 hashes with very strong security. SHA-512 produces a larger 512-bit digest and uses 64-bit operations, so it is often faster on 64-bit CPUs. SHA-256 is the universal default; SHA-512 offers an even larger margin.
What is the difference between SHA-2 and SHA-3?+
SHA-2 uses the Merkle–Damgård construction and is faster in software; SHA-3 uses the Keccak sponge construction and is immune to length-extension attacks. Both are NIST standards and secure; SHA-3 is a structurally different backup.
What is BLAKE2?+
BLAKE2 (RFC 7693) is a modern cryptographic hash that matches SHA-256’s security while being significantly faster — sometimes faster than MD5. It has a built-in keyed (MAC) mode and is used by git, Argon2 and many modern tools.
What is CRC32?+
CRC32 is a fast, 32-bit non-cryptographic checksum used to detect accidental corruption in ZIP files, PNG images and network frames. It is not collision-resistant, so it cannot detect deliberate tampering — use a cryptographic hash for that.
What is a checksum vs a hash?+
“Checksum” is the general term for a value used to detect changes, including non-cryptographic ones like CRC. A cryptographic “hash” (SHA-256, SHA-3, BLAKE2) is a checksum that is also collision-resistant, detecting intentional tampering, not just accidents.
What is a checksum vs a digital signature?+
A checksum proves a file matches a value. A digital signature uses public-key cryptography to prove both that the file is unchanged AND who vouched for it. For maximum assurance, verify a signature (e.g. GPG) in addition to the checksum.
Are my files uploaded anywhere?+
No. All hashing and verification happen entirely in your browser using the Web Crypto API and verified local code. Your files are never uploaded, logged or stored, and you can wipe everything from memory with one click.
Can this tool handle large files?+
Yes. Files are read and hashed in 4 MB chunks in a single streaming pass with a live progress bar, so even multi-gigabyte files can be verified without loading the whole file into memory at once.
How do I verify a Linux ISO or installer?+
Download the file, copy the SHA-256 value from the project’s official page (or its SHA256SUMS file), paste it into the validator, add your file, and check for a ✓ Match. If a GPG signature is provided, verify that too for full authenticity.
What is a SHA256SUMS manifest?+
It is a text file listing one or more files with their SHA-256 checksums (the output of the sha256sum command). This tool can import GNU and BSD-style manifests and verify a whole collection of files against them at once.
Can I auto-detect what type a hash is?+
Yes. Paste a checksum into the Inspector and it identifies the likely algorithm from its length and character set — for example 32 hex characters is MD5, 64 is SHA-256 (or SHA3-256/BLAKE2s), 40 is SHA-1 or RIPEMD-160 — with a confidence level.
What is integrity monitoring?+
Integrity monitoring records baseline checksums of important files and periodically re-checks them. Any unexpected change in a hash signals possible corruption or compromise, making it a core control for security and compliance.
What is digital evidence verification?+
In forensics, a file or disk image is hashed at the moment of acquisition. Recomputing the hash later proves the evidence is unchanged. This tool’s forensic mode produces a fingerprint, timestamp and chain-of-custody-friendly report for such workflows.
Why do two hashes of the same file differ?+
Usually because a different algorithm was used (e.g. comparing an MD5 to a SHA-256), the hash includes extra whitespace, or the files genuinely differ. Make sure you compare the same algorithm and that you copied the full value.
Does hashing change my file?+
No. Hashing only reads the file’s bytes to compute a value; it never modifies the file. It is completely safe to hash any file.
What hash length corresponds to which algorithm?+
By hex length: 8 = CRC32, 32 = MD5, 40 = SHA-1/RIPEMD-160, 56 = SHA-224/SHA3-224, 64 = SHA-256/SHA3-256/BLAKE2s, 96 = SHA-384/SHA3-384, 128 = SHA-512/SHA3-512/Whirlpool/BLAKE2b.
Can I compare two files directly?+
Yes. The comparison tool hashes two files and tells you whether they are identical, and the hash-comparison view highlights character-level differences between two pasted checksums.
Is uppercase or lowercase hash different?+
No — hexadecimal hashes are case-insensitive. abc123 and ABC123 represent the same value. This tool normalizes case when comparing, so a difference in case never causes a false mismatch.
What is a file fingerprint?+
A file fingerprint is a compact, unique identity for a file derived from its cryptographic hash and size. It’s handy for quickly referencing or deduplicating files without sharing the full hash.
Can checksums detect malware?+
Indirectly. If a vendor’s known-good checksum doesn’t match your download, the file may be malicious or corrupted — don’t run it. Checksums also let you compare a suspicious file against databases of known-good or known-bad hashes.
What is supply-chain security?+
It is protecting the path software takes from developer to user — source, dependencies, build and distribution. Verifying checksums (and signatures) of artifacts and dependencies is a key defence against attackers injecting malicious code.
Do I need to verify checksums for HTTPS downloads?+
HTTPS protects data in transit but not against a compromised server or mirror, nor against corruption after download. Verifying the publisher’s checksum adds an independent integrity and authenticity check, so it’s still worthwhile.
Can I export a verification report?+
Yes. You can export TXT, CSV and JSON reports, a printable verification certificate and a PDF report, including a forensic chain-of-custody format — all generated locally in your browser.
What is the most secure checksum algorithm here?+
SHA-512, SHA3-512, Whirlpool and BLAKE2b offer the largest security margins. For most purposes SHA-256 is more than sufficient and universally supported; SHA-3 and BLAKE2 are excellent modern choices.
Is this tool free?+
Yes, completely free with no sign-up, no watermark and no limits. It is a privacy-first, browser-based file integrity and verification platform.
Does it work offline?+
Once the page is loaded, all hashing and verification run locally, so it keeps working without a network connection. Nothing needs to be sent to a server.