Free digital evidence tools — SHA-256 hash calculator & ZIP verifier
Browser-based, privacy-first, no-signup utilities for working with digital evidence — built for lawyers, investigators, OSINT analysts, HR, brand protection, and IP enforcement teams. Every tool runs 100% client-side via the Web Crypto API. Nothing is uploaded. No rate limit. Works offline once loaded.
ProofSnap Free Tools is a small catalogue of browser-based utilities for working with digital evidence: a SHA-256 hash calculator (compute SHA-256, SHA-1, SHA-384, SHA-512 of files or text under FIPS 180-4 / RFC 6234), and a Trust Verifier (independently validate ProofSnap evidence ZIPs — SHA-256 + RSA-4096 + Bitcoin blockchain timestamp + eIDAS qualified timestamp under eIDAS Article 41). Every tool runs 100% in your browser via the Web Crypto API. Nothing is uploaded, no signup, no rate limit. The tools support evidence preparation under FRE 902(14) (US), eIDAS Regulation (EU) No 910/2014, and ISO/IEC 27037 chain-of-custody guidance.
Available now
Open any tool in a new tab — they all work offline once loaded.
SHA-256 Hash Calculator
Calculate SHA-256, SHA-1, SHA-384, or SHA-512 of any file or text. Drag & drop, paste, or compare two hashes.
- ✓Hash any file up to ~5 GB
- ✓Hash any UTF-8 text
- ✓Compare two hashes
Trust Verifier
Drop any ProofSnap evidence ZIP and independently verify SHA-256, RSA-4096 signature, Bitcoin blockchain & eIDAS qualified timestamp.
- ✓Validates 8 integrity checks
- ✓Available in 13 languages
- ✓Open-source verification code
Trust Verifier is open-source — view source on GitHub.
Coming soon
Tools on the roadmap. Bookmark this page or follow ProofSnap to know when each ships.
Court-Evidence Checklist
SOONInteractive checklist that turns into a downloadable PDF: is your screenshot court-admissible under FRE 901/902 or eIDAS?
EXIF Viewer
SOONInspect EXIF, IPTC and XMP metadata of any image in your browser. Useful for OSINT and authenticity checks.
OpenTimestamps Viewer
SOONDrop a .ots file, decode the proof, and verify that the hash was anchored on the Bitcoin blockchain.
DMCA Takedown Letter
SOONGenerate a DMCA takedown letter with placeholders for the infringing URL and the evidence-package hash.
TLS Certificate Inspector
SOONPaste a URL, see the certificate chain, expiry, issuer, and SAN entries. Pairs with web-evidence work.
Chain-of-Custody Template
SOONGenerate an ISO/IEC 27037 chain-of-custody PDF for digital evidence. Pre-filled fields, blank for handover signatures.
Why these tools are free
Each tool here handles one primitive: hashing a file, verifying a ZIP, decoding a timestamp. They are useful on their own and we believe everyone working with digital evidence should have access to them at no cost.
The paid ProofSnap Chrome extension automates the whole evidence pipeline in one click: capture a web page → SHA-256 + RSA-4096 signature + Bitcoin blockchain timestamp + (on Enterprise) eIDAS qualified timestamp + ISO/IEC 27037 chain of custody → self-verifying ZIP that any of these free tools can independently re-check.
Free tools build trust in the cryptography. The paid product saves the hours of manual work per capture.
Free tools vs. paid ProofSnap — what each one does
The free tools each handle one cryptographic primitive. The paid ProofSnap Chrome & Edge extension automates the whole evidence pipeline. Use whichever fits your task.
| Capability | Free Hash Calculator | Free Trust Verifier | ProofSnap Extension (paid) |
|---|---|---|---|
| Compute SHA-256 of a file | Yes | — | Automatic per capture |
| Verify a ProofSnap evidence ZIP | — | Yes | Yes (built-in) |
| Capture a web page as evidence | — | — | One click |
| RSA-4096 digital signature | — | Verifies | Generates & signs |
| Bitcoin blockchain timestamp (OpenTimestamps) | — | Verifies | Anchors per capture |
| eIDAS qualified timestamp (Art. 41) | — | Verifies | Issued via QTSP |
| ISO/IEC 27037 chain of custody | — | Validates | Auto-generated |
| FRE 902(13) / 902(14) ready | Hash only | Validates | Full package |
| Price | Free | Free | From $4.99 one-time / $8.99 mo |
| Signup required | No | No | Yes (7-day free trial) |
QTSP = Qualified Trust Service Provider under eIDAS Regulation (EU) No 910/2014. ProofSnap is not a law firm and does not provide legal advice.
Want hash + blockchain timestamp + court-ready PDF in one click?
ProofSnap captures any web page with SHA-256 + RSA-4096 signature + Bitcoin blockchain timestamp + eIDAS qualified timestamp + chain of custody — all in a self-verifying ZIP. From $4.99 one-time, no subscription required.
Frequently asked questions
Are these tools really free with no signup?↓
Yes. Every tool listed here is a static HTML page that runs entirely in your browser using the Web Crypto API. No file or text is ever uploaded to our servers. There is no signup, no account, and no rate limit. You can view the source of any tool to confirm.
Why does ProofSnap give these away for free?↓
These tools handle a single primitive each — hashing a file, verifying a ZIP, checking a timestamp. ProofSnap, the paid Chrome extension, automates the whole evidence pipeline (capture + hash + sign + Bitcoin blockchain timestamp + eIDAS qualified timestamp + chain of custody) into a single court-ready ZIP. The free tools build trust in the underlying cryptography; the paid product saves you the hours of manual work for every capture.
Can I use these tools in a court case?↓
You can document a hash or verify a ZIP with these tools, but a hash alone is not court evidence. To be defensible under FRE 901/902 (US) or eIDAS Article 41 (EU) you also need a trusted timestamp, a digital signature, and chain of custody. ProofSnap captures all four automatically. ProofSnap is not a law firm and does not provide legal advice.
Will more free tools be added?↓
Yes — see the “Coming soon” list above. Tools are added incrementally. Bookmark this page or follow ProofSnap on LinkedIn to know when each ships.
Does using these tools count as a ProofSnap trial?↓
No. The free tools are completely separate from your ProofSnap account. You can use them without signing up, and using them does not start or affect a ProofSnap trial subscription.