Free tool
Check text before you paste it into AI.
Find keys, card numbers and personal data in a prompt or a file. It runs in your browser and nothing is sent.
Checked in this browser with rule set 2026.10.1. Up to 1,000,000 characters.
Project or client names, separated by commas. They stay in this page too.
Files: .txt, .md, .csv, .tsv, .json, .log, .yaml, .yml, .xml, .ini, .cfg, .conf, .env, .sql up to 1 MB, read here and never uploaded.
Results show here. Nothing is sent anywhere.
How it works
Paste the text.
A prompt, an email, a log or a document you are about to give an AI tool. Or pick a text file.
Check it here.
21 rules look for keys and tokens, card and bank numbers and personal data, with checksums where a number has one.
Remove what should not go out.
Each finding shows its line, a masked value and what to do. Then paste the cleaned text into your AI tool.
Questions
Is the text I paste sent to you?
No. The check runs in this page, in your browser. The text, the file and the words you add never reach our servers, and nothing is saved. Close the tab or press Clear and it is gone.
What does it look for?
21 patterns: API keys and tokens, private keys, passwords written into text, payment card numbers, bank account numbers (IBAN), Aadhaar, PAN, US Social Security numbers, email addresses and phone numbers, plus any words you add.
Does nothing found mean the text is safe?
No. It only knows the patterns it lists, and it does not understand meaning. A client’s name or a plan described in plain words can still be sensitive. Read before you paste.
Which files can it check?
Text files up to 1 MB in UTF-8, such as .txt, .csv, .json, .log or .env. Not Word, Excel, PDF or images.
Does it watch what I type into ChatGPT?
No. This free check has nothing to install and reads only what you paste here. Openn Shield’s paid browser extension is a separate product for companies.