How to Show You Made It First: Give Your Photos and Drafts a Third-Party Date
If someone copies your work, can you show that yours came first? This guide explains how to prepare for that moment, for free, without showing your work to anyone.
Every date you hold can be edited
The trouble with date evidence is simple: anything you can change yourself, the other side can say you changed.
| The date you have | Why it is weak |
|---|---|
| Your CMS publish date | You can set a past date. WordPress documents how.1 |
| Photo metadata (Exif) | Free tools such as ExifTool edit it, and can shift dates in bulk.2 |
| File timestamps | On Windows, a copied file gets a new creation time (the modified time is kept).3 |
| Screenshots | They can be edited like any image. |
Each is better than nothing, but none of them answers "couldn't you have made this up afterwards?" What you need is a date written down by someone other than you, in a form nobody can rewrite later.
Recording with DateSealed
- Open the home page and paste text or pick a file. You can also enter a URL or a SHA-256 you already have.
- Check the SHA-256 shown and press the button to record it. The hash is computed in your browser, so the file or text itself is never sent.
- The record page opens. Download the
.tsr(signed time stamp) and the.ots(Bitcoin proof) and keep them together with the original file.
Each record gets two dates: an RFC 3161 time stamp returned immediately, and an OpenTimestamps record anchored in a Bitcoin block within hours. Once anchored, the date can be checked against the Bitcoin ledger alone, even if DateSealed shuts down. The record page lists the commands to verify it on your own machine.
The limits are 10 records an hour and 50 a day per IP address.
Publishing photos? Use the stamp
Stamp photos records the hash of your original and then, in your browser, makes a copy with a small badge showing the record date and the record page address. The photo itself is not uploaded.
The record points to the original. The stamped copy is a different file, and the badge can be cropped out; on its own it proves nothing. Publish the stamped copy and keep the original safe.
What a record shows, and what it does not
It shows that data matching this hash existed at the recorded time. That is all.
- It does not show that the content is accurate or original.
- It does not show that you made it or own it. The record does not say who created it.
- It does not guarantee legal effect. In Japan, the time stamps with official status come from services accredited by the Ministry of Internal Affairs and Communications (six as of March 2026).4 In the EU, a qualified electronic time stamp is presumed accurate as to date, time and data integrity.5 A DateSealed record is neither.
For the one thing you really need to protect
Use formal options too: a notarised date, copyright registration where your country offers it, or an accredited or qualified time stamp. DateSealed is the cheap, quick first layer for the steady stream of photos, articles and drafts: one more piece of evidence to put next to the rest.
Two things to remember
- Keep the original. DateSealed holds only the hash. Without the original file, the record cannot be tied to anything.
- Record again after every edit. Change one character and the hash changes. On WordPress, the plugin records each publish and update for you.
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WordPress.org, "Write Posts (Classic Editor)" https://wordpress.org/documentation/article/write-posts-classic-editor/ ↑
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ExifTool https://exiftool.org/ ↑
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Microsoft Knowledge Base article KB299648 (how dates are handled when files are copied or moved) ↑
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Ministry of Internal Affairs and Communications, Japan: accredited time-stamping services https://www.soumu.go.jp/main_sosiki/joho_tsusin/top/ninshou-law/timestamp.html ↑
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eIDAS Regulation (EU) No 910/2014, Article 41(2) https://www.legislation.gov.uk/eur/2014/910/article/41/adopted (text as retained in UK law) ↑
Try DateSealed
Paste a paragraph or pick a file. The hash is made in your browser and nothing is uploaded.