Checksum & HMAC Calculator
MD5, CRC-16, CRC-32, SHA & HMAC
Free forever — no sign-up, nothing uploaded. Files never leave your device.
Checksum & HMAC Calculator
MD5, CRC-16, CRC-32, SHA & HMAC
Drop your file here
or browse from your device
Browse filesdocument.pdf
1.2 MB
report.pdf
860 KB
100% private
Nothing is uploaded — everything runs in your browser.
Free forever
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Open the tool and start using it right away.
Local processing
Processing time depends on your input and device.
About this tool
Compute MD5, CRC-16/CRC-32, SHA-1/256/384/512 checksums and HMAC signatures for any text — all locally in your browser.
The BrainCoder Checksum & HMAC Calculator computes cryptographic and non-cryptographic checksums for any text input. It supports popular algorithms including CRC32, Adler32, MD5, SHA-1, SHA-256, and HMAC variants with custom keys. Checksums verify data integrity — if even a single bit changes, the checksum changes completely.
HMAC (Hash-based Message Authentication Code) adds a secret key to the hash computation, creating a tamper-evident seal. If you share data along with its HMAC, the recipient can verify the data hasn't been modified by recomputing the HMAC with the same key. This is fundamental to API authentication, webhook verification, and secure communication protocols.
Non-cryptographic checksums like CRC32 are faster and used for error detection in file transfers, network packets, and storage systems. Our tool covers both use cases in a single interface. All computation happens in your browser — no text, keys, or hashes are sent anywhere.
Key features
Everything you get with Checksum & HMAC Calculator — no premium upsell.
CRC32 and Adler32 non-cryptographic checksums
MD5, SHA-1, SHA-256 cryptographic hashes
HMAC with MD5, SHA-256, and SHA-512
Custom HMAC key input
Multiple algorithms computed simultaneously
Fully client-side with no external dependencies
How to use Checksum & HMAC Calculator
Follow the steps below to use the tool.
- 1
Enter text to checksum
Type or paste the data you want to compute a checksum or HMAC for into the input field.
- 2
Select algorithm
Choose from CRC32, MD5, SHA-1, SHA-256, or HMAC variants. For HMAC, enter your secret key in the key field.
- 3
View results
The tool computes and displays the checksum/hash value. Select multiple algorithms to see all values at once.
- 4
Copy the checksum
Click the copy button next to any result to grab the checksum value for use in integrity verification, API authentication, or logging.
Still free, still private — your files never leave your device.
Launch Checksum & HMAC CalculatorFrequently asked questions
Quick answers before you launch the tool.
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