Firsthand · by CertNode
Own your work’s history
Sign and timestamp your work as you make it. When someone says an AI wrote it, or that you weren’t the one who made it, you have a record of how it actually came to be, one anyone can check for themselves.
Your writing never leaves your device. We seal a fingerprint, not your words.
Write in the editor
Open a document and start writing, or paste in what you already have. Setup takes about thirty seconds. Your words stay in your browser.
Seal a checkpoint when you pause
Whenever you pause, click Save to seal a checkpoint: a fingerprint of that exact version, independently timestamped and anchored so it cannot be backdated. Your document never leaves your device. Only the fingerprint and a few numbers (word count, how much changed) are stored.
One link when you’re accused
A teacher, a client, or a platform says an AI made it. You share one link: a record of every checkpoint over the days you worked, each one something they can verify themselves in under a minute.
What the record proves, and what it doesn’t
It proves
- This exact work existed at these exact times.
- It grew in these steps, over these days.
- Every checkpoint is timestamped and can’t be backdated, not even by us.
- Anyone can verify it independently, with no account and no trust in CertNode.
It doesn’t claim
- It doesn’t detect or score AI. It never guesses.
- It doesn’t read minds or prove who typed each word.
- It doesn’t certify work as “human-made.”
Here’s why that’s enough: a real drafting history is effortless to have and almost impossible to fake. Dripping AI text through fake checkpoints over days is more work than just doing the work. Wholesale-copied work has no such history. Against a detector’s guess, a verifiable record of how you built it is the stronger answer.
Who it’s for
Students
An AI detector flags your essay and your grade is on the line. Detectors are wrong all the time. A real drafting history is something you already have. This just makes it verifiable.
Freelancers
A client refuses to pay, or a platform buries your work, because it “looks AI-made.” Show the timeline of how you built it, sealed as you went.
Writers & creators
Accused of not writing your own book or posts. Keep a running, verifiable record of your process instead of screenshotting version history and hoping.
Simple pricing
Start free. Upgrade in the app when you want to protect more than one document. Cancel anytime.
Free
$0 forever
- One protected document
- Unlimited checkpoints on it
- Shareable public proof report
- Independent verification, no account needed
Firsthand
$5 / month
Around $20 for a school semester.
- As many documents as you need
- Unlimited checkpoints
- Everything in Free
- Cancel anytime
Start with one document, free
Protect a document today at no cost. Keep going for the price of a coffee a month.
Protect your first document