--- title: "File Hash Calculator - Verify Checksums" description: "File hash calculator for SHA-256, SHA-512, SHA-1 and MD5 checksums. Verify any local file privately with drag and drop - no upload." url: https://candoya.com/tools/file-hash/ locale: en type: browser-tool --- # Free File Hash Calculator Category: [Developer](https://candoya.com/tools/dev/) ## What is a file hash calculator? A file hash calculator reads a file's exact bytes and produces fixed-length checksums such as SHA-256, SHA-512, SHA-1 and MD5. You can compare that fingerprint with one published by a software vendor to check whether a download arrived unchanged. This calculator works locally, so the file is never uploaded. The calculator reads your file in small chunks and updates four hash algorithms during the same pass. That keeps memory use steady instead of loading the whole file at once. Paste a vendor's expected checksum afterward and the tool detects its algorithm from the hexadecimal length, then reports a match or mismatch. ## How to use it 1. **Choose a local file** - Drag one file onto the drop zone or select it from your device. Nothing is sent to a server. 2. **Calculate the hashes** - Start the calculation and follow the progress bar while the file is read in chunks. 3. **Copy a checksum** - Copy SHA-256, SHA-512, SHA-1 or MD5 for your records. SHA-256 is the best default for routine integrity checks. 4. **Verify an expected value** - Paste a published checksum. The calculator identifies the algorithm by length and shows whether it matches. ## Who it's for - **Software download verification** - compare an installer, ISO or archive with the checksum published by its vendor. - **Developers and release teams** - fingerprint build artifacts before copying them between machines or storage services. - **Digital preservation** - record hashes now, then test later whether backups or research files changed byte for byte. - **Security triage** - calculate a known file's digest before checking it against trusted internal records. ## Expert note A matching checksum proves that the bytes you received match the bytes used to create the published digest, but only when that expected digest came from a source you trust. An attacker who can replace both a download and the checksum beside it can make a malicious file appear consistent. ## Frequently asked questions ### Is my file uploaded when I calculate its hash? No. Your browser reads and hashes the file locally. The bytes are not uploaded to CanDoYa or sent to another service, which makes the calculator suitable for private files as long as you also trust the browser and device you are using. ### Is this file hash calculator free? Yes. You can calculate and compare file hashes without an account, payment or download. The hashing engine runs inside the page, and each result has its own copy button. ### What is the file size limit? The tool does not impose an artificial file size limit. Practical limits depend on your browser, device, available storage and how long you keep the tab open. Files are read in 4 MB chunks, so the entire file does not need to fit in memory at once. ### Which file hash algorithm should I use? Use SHA-256 for most download and file-integrity checks. It is widely published and has no practical collision attack. SHA-512 is also strong. SHA-1 and MD5 remain useful for matching legacy checksums, but they should not be used where collision resistance is a security requirement. ### How do I check a downloaded file's SHA-256 hash? Choose the downloaded file, calculate its hashes, then paste the SHA-256 value from the vendor into the comparison box. A match means the file bytes agree with that published value. Confirm the checksum came from the vendor's official site or another trusted channel. ### Why does my checksum not match? A mismatch means the file bytes differ from the bytes behind the expected hash. The download may be incomplete, a different version, repackaged or altered. First confirm that you chose the correct file and copied the full checksum without extra hexadecimal values. ### Can two files have the same hash? In principle, yes; that is called a collision. Strong algorithms make accidental collisions extraordinarily unlikely. MD5 and SHA-1 have practical collision attacks, so use SHA-256 or SHA-512 when an adversary might deliberately create different files with the same digest. ## Related tools - [SHA-256 Hash Generator](https://candoya.com/tools/sha-256-hash/) - [Password Generator](https://candoya.com/tools/password-generator/) - [TOTP Code Generator](https://candoya.com/tools/totp-code-generator/) - [Base64 Encode and Decode](https://candoya.com/tools/base64-encode-decode/) - [JWT Generator](https://candoya.com/tools/jwt-generator/) --- *Markdown edition of , published for AI agents and other automated readers. Index of key pages: .*