Personal data leaves your control
Names, emails, NHS and National Insurance numbers end up in a third party’s systems, often outside your data protection agreements.
AI data-leak protection
Use AI freely.
Use AI freely.
Keep personal data out.
Tidewall checks every message the moment you press Send in ChatGPT, Claude, Copilot and other AI tools. Customer details and secrets are caught and redacted in one click, and nothing you type ever leaves your browser.
Checked on your device
No account needed
Rolls out to a team in minutes
Tidewall held this message3 sensitive items found. Nothing has been sent.
sarah.mitchell@…Email addressPersonal dataRedact
943 476 5919NHS numberHealth data · checksum validRedact
sk_live_…API keySecret · never allowedRemove
What the AI will see
Draft a reply to [PERSON_1] ([EMAIL_1]) about her claim. Her NHS number is [NHS_NUMBER_1]. Use key [REMOVED].
Draft a reply to Sarah Mitchell (sarah.mitchell@example.com) about her claim…
Works on ChatGPT · Claude · Gemini · Microsoft Copilot · Perplexity · DeepSeek · Mistral · Grok · Meta AI · NotebookLM · and more
Someone on your team has already pasted customer data into an AI chatbot.
Not out of carelessness. AI tools are useful, and the quickest way to get help with a letter, a spreadsheet or a bug is to paste the real thing.
Secrets get pasted with the code
API keys, passwords and database URLs travel with the snippet someone wanted debugged.
Banning AI just moves it
Blocked at work, people use their phones, where you can’t see or guide anything. Tidewall lets them keep using AI, safely.
How it works
No new app to learn. Tidewall waits for the moment you press Send.
Type as normal
Ask ChatGPT, Claude or Copilot whatever you need. Tidewall stays out of the way.
Tidewall holds what’s sensitive
When you press Send it checks the message on your device and shows what it found, and exactly what the AI would see.
Send redacted, get real answers
Details become placeholders like [EMAIL_1]. In the reply, Tidewall puts the real details back on your screen only.
Try it here
This box runs Tidewall’s real detection engine in your browser. What you type is not sent anywhere; you can check with your browser’s network tools.
Checked in your browser · 0 ms
Found
Catches what matters, ignores what doesn’t
Numbers are checked with their real checksums, so an order number isn’t mistaken for an NHS number.
Personal data
Names, email addresses, phone numbers, postcodes, National Insurance numbers and IP addresses.
Health and financial data
NHS numbers, payment cards, IBANs, sort codes and account numbers, each verified before it’s flagged.
Secrets
API keys and tokens for 20+ services (cloud, AI, payments, code), private keys, passwords and database URLs.
Your own words
Project names, client codes and patterns like ACME-CL-#####, set by you or your IT team.
Your rules
Allow, Warn, Redact or Block for each kind of data. Warnings can ask for a reason before sending anyway.
Approved AI tools
Mark tools as approved or blocked. A blocked tool shows a friendly page pointing to the approved ones.
Private by design. Not by promise.
A tool that stops data leaking shouldn’t collect your data. So Tidewall doesn’t.
- Every check runs inside your browser, in about a millisecond.
- What you type is never stored, never sent, never seen by us.
- No analytics, no tracking, no remote code. The extension makes no network requests.
- The activity list keeps only the kind of data and what happened, on your device.
- Read the one-page privacy policy
For teams: one policy, every browser
Push Tidewall with Google Workspace or Microsoft Intune and set the rules once. Staff can see them but not switch them off.
- Company rules for each kind of data
- Approved and blocked AI tools
- Your client codes and project names
- Admin console with reports: coming soon
{ "orgName": "Acme Health", "actions": { "email": "redact", "nhs": "redact", "card": "block", "secret": "block" }, "customWords": ["Project Neptune", "ACME-CL-#####"], "sites": { "character.ai": "blocked" }, "requireReason": true }
Simple pricing
Free for individuals. A few pounds a person for teams. Prices exclude VAT.
Personal
Free
- All detection, on your device
- Redact, warn or block, your way
- Your own words and patterns
- Approve or block AI tools
Team
£3 per user / month, billed yearly
- Everything in Personal
- Company rules pushed to every browser
- Settings locked for staff
- Approved and blocked AI tools
- Rollout guide and setup call
- From 5 users · £4 billed monthly
Business
£6 per user / month, billed yearly
- Everything in Team
- Admin console and reports
- AI-tool discovery
- Policies by team
- SSO and audit export
Founding customers: half price for your first year, for the first 25 organisations, in return for a short case study.
Questions
Does Tidewall see what I type?
No. The checks run inside your browser. Tidewall never stores or sends your messages, and the extension makes no network requests of its own.
Which AI tools does it work with?
ChatGPT, Claude, Gemini, Google AI Studio, NotebookLM, Microsoft Copilot, Perplexity, DeepSeek, Mistral Le Chat, Grok, Meta AI, Poe, Hugging Face Chat and more. We add tools as they become popular.
Will it slow me down?
Checks take about a millisecond. Messages with nothing sensitive go straight through; you only see Tidewall when it has found something.
Does it catch everything?
No tool can. Tidewall verifies numbers with checksums, recognises names from many cultures and context, and lets you add your own client codes and project names. It turns “we hope people are careful” into a control you can show an auditor.
Can staff turn it off?
On the Team plan, rules are set by your organisation through your browser management and can’t be paused or changed by staff.
Is it compliant with UK GDPR?
Tidewall helps you meet your obligations by stopping personal data reaching AI tools you don’t have agreements with. Because it doesn’t collect personal data itself, it doesn’t add a new processor to your records.
Does it check files I upload?
Not yet. Tidewall checks text you type or paste. File and image checks are on the roadmap.
Use AI freely. Keep personal data out.
Free for individuals. Set up for a whole team in minutes.