What a hash is
A cryptographic hash is a one way function that maps any input to a fixed length output. For example, SHA256 always returns a 64 character hexadecimal string. Good hash functions are deterministic, fast to compute, and hard to reverse. They also have the avalanche effect where tiny input changes produce very different outputs—hence why a file diff plus a checksum often provides the clearest audit trail.
Why hashing matters
- File integrity: Confirm that a download was not corrupted. Compare your local SHA256 with a publisher’s checksum (see verification steps).
- Deduplication: Detect identical content across folders or datasets by comparing MD5 or SHA256; manage large manifest lists with the CSV Viewer & Editor when needed.
- Authentication with HMAC: Prove that a message came from someone who knows a shared secret (ideal for webhooks and API signatures).
- Password storage: Store salted, slow hashes rather than plain text. Generate strong credentials with the Random Password Generator; salting prevents rainbow table attacks.
How to generate hashes in SnipText
- Open the Hash Generator.
- Paste text or drag and drop files. You can add an optional salt to the text input.
- Click Generate to see MD5, SHA1, SHA256, and HMAC in one view.
- Use Copy or Download to save results. Export a .sha256 list for batch file checks (you can format these for docs with the Quick Table Generator).
For longer writing projects, pair this with the Word Counter and the Whitespace and Formatting Cleaner to keep your workflow tidy.
How to verify a checksum
- Find the publisher’s SHA256 on the download page.
- Hash your downloaded file using the tool. You can paste files directly from the clipboard.
- Paste the expected SHA256 into the Verify box. If it matches, you will see a clear match signal.
You can also import a checksum file where each line is formatted like hash filename. The table will show match or no for each file; for quick cleanup of pasted lists use Whitespace Cleaner or remove stray breaks with Remove Empty Lines.
- Hash the final file: Do not hash partial downloads or archives before extraction unless that is the published checksum.
- Use SHA256: SHA256 is the common choice for file integrity. MD5 can collide and should only be used for quick dedupe or non security tasks.
- Beware whitespace: When pasting a published checksum, remove stray spaces and line breaks (try the Whitespace Cleaner).
When to use HMAC
HMAC adds a secret key to the hashing process. It solves a different problem than plain hashing. HMAC proves that the sender knew the key and that the content was not changed in transit. Use HMAC for webhooks, API signatures, and message authentication. In the SnipText tool you can select HMAC SHA256 or HMAC SHA1 and supply your key locally (generate long random keys with the Password Generator).
What salting does
Salting adds unique random data to each password before hashing. It makes precomputed rainbow tables useless. Salts do not need to be secret, but they must be unique per record. Our tool offers prefix, suffix, or both for quick experiments, but production systems should use per user random salts with slow KDFs like bcrypt, scrypt, or Argon2.
Best practices and pitfalls
- Use SHA256 for integrity: Prefer SHA256 over MD5 and SHA1 for file checks.
- Do not store raw passwords: Use salted, slow hashing algorithms designed for passwords (and create strong passphrases with the Password Generator).
- Separate use cases: HMAC for authenticity, hashes for integrity, encryption for secrecy.
- Keep it private: SnipText tools run in your browser, so text and files never leave your device—see our Privacy Policy.
Try the tool
Open the Hash Generator, paste text or drop files, and compare results instantly. For documentation style exports and reports, you can also use the Quick Table Generator to format checksum lists for sharing, or view structured manifests with the CSV Viewer & Editor.
FAQ
- Is the SnipText Hash Generator free and private?
- Yes. It runs completely in your browser, with zero uploads (details in our Privacy Policy).
- Can I hash multiple files at once?
- Yes. Drag and drop several files to get a table of SHA256 values and export a .sha256 list (then format for reports with the Quick Table Generator).
- Does it support HMAC?
- Yes. Enter a key and choose HMAC SHA256 or HMAC SHA1 for text inputs (create strong keys with the Password Generator).
- Where can I learn more security basics?
- Start with our practical tools and guides: Best AI Writing Tools for workflow choices, the Code Diff Checker for version comparison, and the Random Password Generator for strong credentials.