Context Budget Splitter
Split long text into character-budget chunks for LLM context windows. Free browser tool, no upload. Estimate tokens locally.
Runs locally in your browser. Your input is not uploaded to DevToolMate servers.
Chunking
Set Chunk size (64 to 200,000 characters) per chunk. Token estimates are approximate heuristics.
Developer Quick Tips
- Paste text, set chunk size (64-200k chars), and get numbered chunks with token estimates, no API calls needed.
- Use output to plan how much fits in your model's context window (GPT-4o, Claude, Gemini, etc.).
- Token counts are approximate; pair with Token Counter for exact billing estimates before sending to APIs.
- Chunk for RAG retrieval by setting a character budget that leaves room for query + system prompt.
- Press Ctrl/Cmd + Enter to split after pasting input.
Frequently asked questions
What is a context window?
A context window is the maximum amount of text (measured in tokens) that an LLM can read and process in a single request. For example, GPT-4o has a 128k token context window, Claude 3.5 Sonnet has 200k tokens. Context Budget Splitter helps you estimate how much of your text fits within that limit.
How do I know what chunk size to use?
Start with your model's context window size (check your provider's docs). Subtract ~20% for system prompts, instructions, and response space. Convert the remaining tokens to characters (rough rule: 1 token ≈ 4 characters). Set that as your chunk size. Context Budget Splitter will show you token estimates per chunk.
Does Context Budget Splitter upload my data?
No. Context Budget Splitter runs entirely in your browser. Your input is never uploaded to DevToolMate servers or external APIs. Processing stays on your device.
Can I use this for RAG or document retrieval?
Yes. Set your chunk size to fit your model's context window minus space for the query and system prompt. Context Budget Splitter will split your documents into retrieval-ready chunks with token estimates, so you know how many chunks fit in a single API call.
Are the token estimates exact?
No. Token counts are approximate heuristics for planning. They vary by model and tokenizer. Always verify against your provider's tokenizer before billing. Use Token Counter for more detailed estimates.
Related tools
- Token Counter: Free token counter and content length calculator. Estimate prompt tokens and string length locally in your browser with character, word, and byte counts. No upload, no account.
- Prompt Diff: Compare two prompts line by line in your browser. Free, no upload. Private, browser-based developer tool.