NO. T-0302 · AI Toolkit
AI Context Window Checker
- Free · no signup
- Runs in your browser
About this tool
Will my document fit in GPT, Claude or Gemini? See it before you paste.
Long PDFs, transcripts and reports often break AI chats with “message too long”. Load your text or file and see, for every model, how much of the context window it uses, how much room is left for the answer, and how many parts to split it into when it doesn't fit.
How to use it
- 01Paste the text or load a Word, PowerPoint, Excel or text file.
- 02Keep room for the answer and your instructions.
- 03See which models fit — or how much to cut and into how many parts to split.
No more “too long” errors
Know before you paste which model can take your document.
Plan the split
Get the number of parts needed for smaller context windows.
Local & private
Documents are read on your device only.
Frequently asked questions
What is a context window?
It's the maximum number of tokens a model can consider at once — your prompt, documents, chat history and its own answer together.
Why reserve space for the answer?
The answer is part of the same window. If your document fills it, the model has no room left to reply.
My file doesn't fit — what now?
Pick a model with a larger window (e.g. 1M tokens), cut parts you don't need, or split it into chunks with the Text Cleaner & Chunker.
Guetix · Custom
Need AI that reads your documents?
I build document Q&A and RAG systems that work on files of any size.
I'm Hamza — a full-stack developer building fast, SEO-first products.
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Results are estimates for informational purposes only and are not financial, tax or legal advice.