Introduction
A cryptographic hash condenses any file into a short, fixed-size string called a digest. The digest changes entirely when a single bit is altered, making it ideal for tamper detection and authenticity checks. For example, matching the published digest of an operating-system image confirms you downloaded it intact. Nevertheless, a valid digest cannot prove the source itself is trustworthy.
This tool lets you drag and drop a file, pick from common algorithms, and optionally mix in a random 16-byte salt that makes identical files produce unique digests. For instance, salting separate log archives stops rainbow-table lookups. Be cautious: predictable or reused salts offer little extra security. You may also convert the output to uppercase for scripts that require case-sensitive checks.
You typically run a digest before publishing archives, firmware, or research datasets so recipients can reconfirm integrity later. Combine the result with signed release notes or secure channels. *Never rely on a digest alone to guarantee safety; also validate provenance and digital signatures.* System administrators also archive nightly hashes to detect silent bit-rot over time.
Technical Details:
The interface runs entirely in your browser on a reactive engine, streaming file bytes into a lightweight cryptographic library powered by the Web Crypto API. No data leaves the session, and state persists through URL parameters for shareable settings. A single-threaded worker computes the digest without blocking scrolling. [oai_citation:0‡script.js](file-service://file-HmsQrKn5crxiatiWFnKMCQ)
Client-Side Processing
All hashing occurs locally using the browser’s cryptographic primitives, so sensitive files never touch an external server, meeting strict compliance requirements.
Drag-and-Drop Upload
Drop any document on the highlighted zone; progress indicators switch from spinner to green check once parsing completes, providing quick visual feedback.
Salted Hashing
Append or prepend a 16-byte random value with one click, defeating pre-computed lookup tables and making each digest unique even for identical content.
Algorithm Selector
Choose from twelve industry-standard algorithms, including modern SHA-3 variants, directly from the “Hash type” list to match your compliance policy.
Instant Clipboard Copy
Click the blue Copy button; the digest transfers to the clipboard and the icon briefly turns into a green check, confirming success without extra dialogs.
Shareable Link
Parameters such as algorithm and salt sync to the address bar, letting you bookmark or share pre-filled settings for reproducible hashing workflows.
Step-by-Step Guide:
Follow these quick steps to create and copy a digest.
- Drag a file onto the drop zone or click browse to select it manually. [oai_citation:1‡app.html](file-service://file-YRNvgUQgkRPav6TR3RB18j)
- Wait for the spinner to finish; a green check confirms successful loading.
- Open the Hash type list and pick your preferred algorithm.
- Click Advanced, then press Random to generate a salt optional.
- (Optional) Flip the Uppercase switch if your workflow demands capitals.
- Press the blue Copy button to send the digest to your clipboard and share it securely.
FAQ:
Find concise answers to common questions below.
Is my data stored?
No. Files are processed only in your browser; nothing leaves your device.
Why add a salt?
A salt breaks deterministic hashing, preventing attackers from using pre-computed tables to guess original content.
Digest differs across tools?
Ensure you select identical algorithms and casing; differences usually stem from mismatched settings or hidden salts.
Can I hash large files?
Yes. Streaming reads handle multi-gigabyte inputs, though browser memory limits may eventually apply.
Uppercase option use?
Some scripts treat lowercase and uppercase digests differently. Toggle to uppercase for compatibility with such tooling.
Troubleshooting:
Resolve common issues quickly.
- No digest appears: Check that the file finished loading before switching algorithms.
- Digest copies blank: Your browser may block clipboard writes; allow clipboard permission.
- Hash never completes: Very large files can exhaust memory; split the file and hash parts separately.
- Salt field locked: Collapse and reopen the Advanced panel to reset the control bindings.
- Unexpected “undefined” result: Refresh the page to clear stale parameters in the URL.
Advanced Tips:
Enhance your workflow with these expert suggestions.
- Bookmark a fully populated URL to share reproducible settings with teammates.
- Use unique salts per file batch to thwart correlation attacks.
- Automate uploads via the command line and compare digests programmatically.
- Store historical digests in a version-controlled manifest to detect silent corruption.
- Pair the digest with a detached signature from a hardware token for stronger authenticity.
Glossary:
Key terms used throughout the guide.
- Digest
- Fixed-length string output representing the original data fingerprint.
- Salt
- Random value added to data before hashing to increase uniqueness.
- Algorithm
- Mathematical procedure that transforms data into a digest.
- Clipboard API
- Browser interface that enables reading and writing to the system clipboard.
- Checksum
- Generic term for values used to verify data integrity during transfer.