Paste Guard
Check text for secrets before you paste it into ChatGPT, Claude, Slack or email.
0 / 50,000 characters
Something not working?
Tell us what went wrong — it helps us fix the tool. Only what you type below is sent; your text never leaves your device.
Need more power? Meet Paste Guard Pro
One-time payment. Yours forever. No subscription.
| Feature | Free | Pro |
|---|---|---|
| Characters per check | Up to 50,000 | Unlimited |
| Secret categories detected | All 10 | All 10 |
| Custom words to mask | Up to 10 terms | Unlimited |
| Copy sanitized text | Yes | Yes |
| Restore map (in-memory) | Yes | Yes |
| Ads | Shown on page | Ad-free |
| Updates | — | Lifetime free updates |
Frequently asked questions
Is my text uploaded to your servers?
No. Paste Guard runs entirely inside your browser using JavaScript. Your text never leaves your device. You can verify this in your browser's network panel — or simply disconnect from the internet after the page loads and keep checking.
What kinds of secrets does Paste Guard detect?
OpenAI and Stripe API keys, GitHub and Slack tokens, AWS access key IDs, JSON Web Tokens (JWTs), private key blocks, email addresses, credit card numbers (validated with the Luhn check), credentials embedded in URLs, passwords and secrets in key = value assignments, Bearer tokens and other long high-entropy tokens — plus any custom words you add, such as names or project codenames.
What is the restore map, and where is it stored?
Every secret is replaced by a stable placeholder such as [API_KEY_1], and the same value always gets the same placeholder. The restore map (placeholder to original value) lives only in the page's memory so you can verify what was masked with "Show originals". It disappears when you reload or close the tab, and it is never sent anywhere.
Is there a character limit?
The free version checks up to 50,000 characters per paste. Paste Guard Pro ($29 one-time) removes the limit and adds unlimited custom words.
Does a SAFE verdict guarantee my text is safe to share?
No. Detection is pattern-based — it catches the common secret formats, but it cannot know every credential format or recognize a secret written in an unusual way. Always read the sanitized text once before pasting it anywhere.