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AI Tools

Tools that use AI, and one place to choose which AI: none, your browser’s built-in model, free models or your own key. Nothing goes through our servers.

Four ways to use AI here

From none at all to your own key. Whichever you pick, your text goes from your browser straight to the model, never through our servers.

  1. No AI

    Every tool works without AI. The maths, checks and charts are the page’s own code, in your browser.

    FreeNothing sent

  2. Built-in AI

    Your browser’s own model, Gemini Nano in desktop Chrome. A one-time download, then it works offline.

    FreeStays on this device

  3. Free models

    Sign in with OpenRouter and pick a free model. Up to 50 requests a day (1,000 once you’ve bought $10 of credit), and free providers may log what you send.

    FreeSent to OpenRouter

  4. Your own key

    Stronger models, billed to your key: usually a fraction of a cent a run. Private mode sends only to providers that keep nothing.

    Pay per usePrivate mode

Connect a model

For free models or your own key. OpenRouter gives one key for hundreds of models, with a spending limit you set when you sign in.

You’ll come back here with a key.

Off: the key is forgotten when you close this tab.

OpenAI, Anthropic or Gemini key? Add it in Settings → AI.

Pick a model

OpenRouter prices on Oct 10, 2026, per million tokens

The bars: one run on a 3,000-word document with a 750-word answer (about 4,500 tokens in and 1,000 out). Free models allow 20 requests a minute and 50 a day (1,000 after $10 of credit). Any other model: Settings → AI.

On: OpenRouter sends your text only to providers that keep nothing after answering and never train on it (zero data retention). It can rule out a few models or providers; you’ll be told if a run can’t go.

Spending guards

Before a run that could cost more than $0.05, you see the exact text and the most it can cost. Runs stop once this tab has spent $0.50. Nothing is retried on its own. Change them

While a key is stored in this browser, Google Analytics doesn’t load on this site. How AI features handle your text

AI Tools

What each tool sends

Only when you use its AI, and only to the model you chose. With the built-in AI it never leaves this device.

ToolWhat it sends
BMI CalculatorBuilt-in AI and upYour question, only when the page can’t read it without AI; for “Explain my result”, the result’s figures
Blood Sugar LogBuilt-in AI and upThe insights’ facts and your question, never your readings
Mortgage CalculatorBuilt-in AI and upYour question, only when the page can’t read it without AI; for “Explain my result”, the result’s figures
Percentage CalculatorBuilt-in AI and upYour question, only when the page can’t read it without AI; for “Explain my result”, the result’s figures
Unit ConverterBuilt-in AI and upYour question, only when the page can’t read it without AI; for “Explain my result”, the result’s figures
Markdown EditorBuilt-in AI and upThe text you select, or the whole page, with what you asked for (summarise, rewrite, proofread, translate, write)
Mermaid Diagram EditorBuilt-in AI and upYour description of a diagram, or the open diagram’s code to explain or fix
Resume CheckerBuilt-in AI and upYour resume without contact details: the bullets being rewritten, or all of it for a summary; for tailoring, the job title too
Time Zone ConverterBuilt-in AI and upYour question, only when the page can’t read it without AI; for “Explain my result”, the result’s figures

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