Last updated: March 2026
File timestamping tools prove that a digital file existed at a specific date and time. They work by creating a cryptographic fingerprint (hash) of your file and having it certified by a trusted authority. There are two main approaches: RFC 3161 timestamps (certified by a Timestamp Authority, recognized under eIDAS) and blockchain timestamps (anchored on Bitcoin or Ethereum, verified by the network). This guide compares 7 tools across price, speed, privacy, legal recognition, and ease of use — so you can choose the right one for your situation.
Whether you need to prove a creation date for copyright purposes, protect a trade secret, or create an audit trail for compliance, file timestamping is the foundation. But the landscape is fragmented: some tools use blockchain, others use RFC 3161; some are free, others charge per timestamp; some are instant, others take 24 hours. This guide helps you cut through the noise with an honest, side-by-side comparison — including our own tool, ProofStamper, with its strengths and limitations clearly stated.
| ProofStamper | OriginStamp | Bernstein | OpenTimestamps | FreeTSA | e-Soleau (INPI) | Email-to-self | |
|---|---|---|---|---|---|---|---|
| Technology | RFC 3161 | Blockchain (Bitcoin + Ethereum) | Blockchain + qualified TSA | Blockchain (Bitcoin) | RFC 3161 | SHA-256 + INPI archive | None |
| Price | Free (Pro: $9/mo) | Paid (enterprise pricing) | From ~$9/project | Free (open-source) | Free | $16 per 5-year period | Free |
| Speed | ~30 seconds | Up to 24 hours (batched) | ~10 min | 1-4 hours | ~30 seconds | Minutes | Instant |
| File privacy | Zero-knowledge (file never leaves device) | Zero-knowledge (hash only) | Encrypted upload (stored on server) | Zero-knowledge (hash only) | Zero-knowledge (hash only) | INPI stores a copy | N/A |
| File format | Any | Any | Any | Any (technical) | Any (technical) | PDF only | Any |
| Account required | No | Yes | Yes | No | No | Yes | No |
| Legal recognition | eIDAS Art. 41 (EU-wide) | Blockchain evidence (varies by jurisdiction) | Blockchain + EU/China qualified TSA | Blockchain evidence (varies) | eIDAS Art. 41 (EU-wide) | France only | Very weak (easily disputed) |
| Independent verification | Yes (OpenSSL) | Yes (blockchain explorer) | Yes (blockchain + TSA) | Yes (blockchain explorer) | Yes (OpenSSL) | Via INPI only | No |
| Best for | Individuals, freelancers, quick daily use | Enterprises, compliance, audit trails | Startups, IP portfolios, R&D teams | Developers, privacy maximalists | Developers, technical users | French creators (pre-patent) | Nothing (not recommended) |
| Weakness | Uses FreeTSA (not a qualified eIDAS TSA) | Not instant; enterprise pricing opaque | Paid; stores files on server | CLI only; no UI; slow | No UI; requires command-line | France only; PDF only; paid | No cryptographic proof |
Pricing and features are based on publicly available information as of early 2026. Tools evolve — always verify on the official website. ProofStamper is our product; we have included it honestly alongside competitors, with its limitations clearly stated.
A web-based tool that creates RFC 3161 certified timestamps for any file, for free, in ~30 seconds. Your file never leaves your device — only its SHA-256 hash is sent to a Timestamp Authority (FreeTSA). You receive a Proof Pack containing a human-readable PDF certificate and a cryptographic .tsr token.
Best for: Freelancers, creators, and anyone who needs quick, free, private proof of file existence for everyday use.
A blockchain-based timestamping platform founded in 2013 by researchers in Germany. It anchors file hashes on Bitcoin and Ethereum blockchains using Merkle trees, creating decentralized, tamper-proof proofs.
Best for: Enterprise compliance, audit trails, organizations needing decentralized proof at scale.
A Munich-based platform combining blockchain timestamps (Bitcoin) with qualified TSA timestamps (EU and China) for intellectual property protection. Project-based approach with chained certificates. Mentioned in the WIPO White Paper on Blockchain and IP (2022).
Best for: Startups, R&D teams, and businesses managing IP portfolios who need the strongest possible legal proof.
An open-source, free protocol for creating Bitcoin blockchain timestamps, created by Bitcoin Core developer Peter Todd. Command-line tool and library — no web UI, no account, no fees.
Best for: Developers, privacy maximalists, and technically proficient users who want maximum decentralization with zero cost.
A free, open RFC 3161 Timestamp Authority that provides trusted timestamps via standard protocols. FreeTSA is the TSA backend that ProofStamper (and many other tools) uses.
Best for: Technical users who want raw RFC 3161 timestamps without any intermediary, and developers building timestamping into their own applications.
The French National Institute of Industrial Property's official digital envelope service for proving prior creation. The paper version was discontinued in April 2024 — all deposits are now online.
Best for: French creators and inventors who need an official, state-backed proof of creation.
The practice of emailing a file to yourself to 'prove' it existed at the email's timestamp. Often cited as a free alternative but widely considered unreliable.
Best for: Nothing. This method is not recommended. Use any of the tools above instead.
This is the fundamental architectural choice in file timestamping. Both approaches prove a file existed at a date, but they do it differently.
A Timestamp Authority (TSA) receives the hash of your file, signs it with its private key along with the current time, and returns a signed token. The proof relies on the TSA's credibility and the integrity of its signing key. It's recognized under the EU's eIDAS regulation (Article 41).
The hash of your file is anchored in a blockchain transaction (typically Bitcoin). The proof relies on the blockchain's immutability and the consensus of thousands of independent nodes.
| RFC 3161 | Blockchain | |
|---|---|---|
| Trust model | Centralized (trust the TSA) | Decentralized (trust the network) |
| Speed | Instant (~seconds) | Slow (minutes to hours) |
| Legal recognition | Explicit in eIDAS (EU) | Evolving (accepted in some jurisdictions) |
| Longevity | Depends on TSA's continued operation | Permanent (as long as the blockchain exists) |
| Cost | Free or low-cost | Free (OpenTimestamps) to expensive (enterprise) |
| Verification | Requires TSA's public certificate | Requires blockchain access |
| Environmental impact | Negligible | Significant (Bitcoin mining) |
Neither is universally better. RFC 3161 is faster, cheaper, and has clearer legal standing today. Blockchain is more decentralized and potentially more durable long-term. Some tools (like Bernstein) combine both for maximum coverage.
We evaluated each tool across 6 criteria:
ProofStamper is our product. We have scored it alongside competitors using the same criteria. We score lower on legal recognition (advanced, not qualified eIDAS timestamp) and blockchain durability (centralized TSA model). We score higher on price, speed, privacy, and ease of use.
File timestamping creates a certified proof that a specific file existed at a specific date and time. It works by calculating a cryptographic hash of your file and having it certified by a trusted authority — either a Timestamp Authority (RFC 3161) or a blockchain network.
Neither is universally better. RFC 3161 is faster, has clearer legal standing under eIDAS, and costs less. Blockchain is more decentralized and potentially more durable. Some tools combine both approaches.
Yes. ProofStamper, OpenTimestamps, and FreeTSA are all free. ProofStamper is the easiest to use with a web interface. OpenTimestamps and FreeTSA require command-line tools.
No. A timestamp proves the file existed at a specific date. It does not prove ownership. However, proving prior possession is strong evidence in copyright and IP disputes.
Bernstein with qualified TSA offers the strongest combination: blockchain plus qualified eIDAS timestamp. For RFC 3161 alone, tools using a qualified TSA have the highest standing. ProofStamper uses advanced (not qualified) timestamps, admissible under eIDAS Article 41.
For RFC 3161 tools: your proof remains verifiable with OpenSSL. For blockchain tools: the proof is on the blockchain permanently. For hosted services like Bernstein or e-Soleau: it depends on the organization's continued operation.