How to timestamp a file on Windows or Mac, step by step

Before you start: get the file ready

A timestamp covers one exact set of bytes, so settle the file first.

• Use the version you want to date. If you will keep editing, timestamp now and again later. Each saved version is a different file with a different fingerprint.
• Don’t re-save it first. Opening a file is fine, but saving, exporting or converting it creates a new file. Timestamp the original export.
• Several files? One TimeBind holds up to 10 files, each with its own fingerprint. A whole folder? Put it in one zip and timestamp that zip, then keep that exact zip. Zipping the same folder again usually gives a different file.
• Keep it somewhere safe. The timestamp keeps no copy, so back the file up yourself.

Step by step: timestamp a file with TimeBinder

1. Open the TimeBinder app at app.timebinder.io on Windows, Mac or Linux. Use a current browser.
2. Add your file or files by dragging them in or choosing them. Your browser makes the fingerprint on your device, so the file stays on your device. Large files can take longer because your computer does the work.
3. Choose the type of TimeBind. Pooled (1 Token) is batched with other fingerprints and usually recorded within 24 to 48 hours, often sooner, depending on Bitcoin network activity. ASAP (3 Tokens) gets its own Bitcoin transaction, broadcast straight away, and can be checked independently of TimeBinder.
4. Confirm. Your first Pooled TimeBind is free, with no credit card required.
5. Save the Proof of Time Certificate once it is ready, and store it next to the original file. Make a second copy of both.

How blockchain timestamping works at TimeBinder explains each step in more detail, and how long a Bitcoin timestamp takes to confirm explains the wait.

Optional: check the fingerprint yourself first

You don’t need to, but it is a useful habit. You can calculate the same SHA-256 fingerprint with your computer’s own tools and compare it later.

• Windows (PowerShell): Get-FileHash .\myfile.pdf -Algorithm SHA256
• Mac (Terminal): shasum -a 256 myfile.pdf
• In your browser: use our free SHA-256 hash checker.

Our guide to checking a SHA-256 checksum on Windows, Mac and Linux covers more options.

Check it again later

A timestamp is only useful if you can show it still matches. Months later, drop the same file into the verifier, or recalculate its fingerprint and compare it with the certificate. If it doesn’t match, you are almost certainly checking a different copy, such as a re-saved, resized or exported version. See how to check a file still matches its fingerprint.

Mistakes that break a timestamp

• Timestamping an edited copy. Date the original, not a later version.
• Losing the original. The certificate can’t recreate the file.
• Renaming is fine, editing is not. Changing the file name does not change the fingerprint, but changing any content does.
• Expecting more than it shows. A timestamp shows when a file existed, not who wrote it or whether AI was used. Keep drafts and working files too. See how to prove a file existed before a date for what else helps.

Timestamp your first file free

Your first Pooled TimeBind is free, with no credit card required. After that, TimeBinds start from US$5, and an ASAP TimeBind is US$15. See plans and pricing