Large CSVs, multi-MB JSON files, long documents — standard AI interfaces struggle with them. This guide covers the browser tools that pre-process, chunk, convert, and optimize large data for AI models so you stop hitting context limits.
You don't need an API key, a subscription, or a server to supercharge your AI workflow. These 10 browser-based tools handle token counting, prompt engineering, large dataset conversion, and model comparison — all locally, all free.
Count tokens for GPT-4, Claude, Gemini and more. Paste any text or entire documents to see exact token usage before sending to an AI model.
Build structured, high-quality prompts for ChatGPT, Claude, and Gemini. Define role, context, task, format, and constraints in a guided form.
Convert large JSON datasets into clean, token-efficient AI prompts. Perfect for feeding structured data to ChatGPT, Claude, or Gemini without wasting context.
Transform CSV files and large tabular datasets into AI-ready prompts. Control which columns to include, row limits, and output format to stay within token budgets.
Generate professional system prompts for AI assistants, chatbots, and agents. Choose persona, tone, domain, and constraints to produce a production-ready system prompt instantly.
Compare GPT-4o, Claude 3.5 Sonnet, Gemini 1.5 Pro, Llama 3, Mistral, and more side-by-side. Context window, pricing, strengths, speed, and best use cases.
QR Codes aren't just for links! You can encode any text, like a secret message or a funny joke, for your friends to discover.
Paste your document or prompt to see instantly which AI models can handle it within their context window — and which can't.
Filter models:
OpenAI
Anthropic
Meta
Mistral
Alibaba
Token counts are estimates (±5%). Context limits shown are the maximum input context for each model as of 2026 — check provider docs for latest values.