Pricing
Editor Pricing
The core editor is entirely free with no restrictions. Only the AI chat assistant costs credits.
4 min read·Pricing
What\'s free vs what costs credits
| Feature | Cost | Notes |
|---|---|---|
| Upload PDF, Markdown, or any file | Free | No size limit, no rate limit |
| Freehand drawing & highlighting | Free | Unlimited layers, any colour |
| Sticky text notes | Free | Unlimited per page |
| Erasing & clearing annotations | Free | |
| Saving & re-opening files | Free | Stored locally in browser |
| Rendering Markdown with LaTeX math | Free | Live preview |
| AI chat — text message | Credits | Flat rate per message sent |
| AI chat — with selection context | Credits | Slightly higher based on selection size |
How AI chat credits are counted
You are charged once per message you send. Reading AI responses is free. The exact credit amount depends on two variables:
Base rate per message
A flat credit cost applies to every message, regardless of length. This covers the AI model\'s inference cost.
Selection context surcharge
When you send a message with a selection linked (text or an image region), that selection is included as context. Larger selections cost slightly more because the AI has to process more input tokens.
Keep selections focused. Selecting an entire page costs more than selecting just the specific equation or paragraph you want help with. Tighter selections = lower cost per message.
Running low on credits
If your credit balance reaches zero, the annotation tools remain fully functional — you can still draw, highlight, and add notes without any restrictions. Only the AI chat button will be disabled until you top up.
Top up at any time from the Balance page. Credits purchased are added instantly with no delay.
There is no monthly minimum or subscription. Buy what you need, use it at your own pace. Credits never expire.