AI Era Tools & Guides
AI Tools for ChatGPT, Claude, and Gemini
Free tools and reference guides for the major AI models. Check if your prompt fits, convert between tokens and words, compare context windows across providers. Everything runs in your browser with no signup.
AI Prompt Word Counter
Paste any prompt. See token count, context fit percentage, and API cost for GPT-5.5, Claude, Gemini and every major model side by side.
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Tokens to Words Converter
Convert between tokens and words for any AI model. Enter either value, pick a tokenizer, see the exact equivalent with context-window percentage.
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ChatGPT Word Limit
Every ChatGPT model input and output limit explained. GPT-5.5, GPT-4o, GPT-4.1, o3. What fits, what breaks, what it costs.
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Claude Word Limit
Claude Fable 5, Opus 4.8, Sonnet 4.6 and Haiku 4.5 context windows by the numbers. 750,000-word Fable ceiling, pricing math, caching tricks.
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Gemini Word Limit
Gemini 3.1 Pro has the largest mainstream context window: 2 million tokens, about 1.5 million words. What that means in practice.
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Grok Word Limit
Grok 4.3 is the April 2026 flagship at 1M tokens; Grok 4.1 reaches 2M. Limits across every variant.
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Llama Word Limit
Meta Llama 4 Scout has the largest context window of any production LLM: 10 million tokens. Open-weight too.
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DeepSeek Word Limit
The cheapest frontier-tier API in 2026. V4 handles 1M tokens at $0.30 per million.
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Perplexity Word Limit
Perplexity routes across GPT, Claude, and Sonar. Effective limits by tier explained.
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Mistral Word Limit
Europe's leading AI lab. GDPR-compliant, open-weight options, 256K context. The EU-compliance pick.
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Context windows at a glance
Every AI model has a ceiling on how much text it can process in a single request. Here's where the major models stand as of 2026.
| Model | Context (tokens) | Approx. words | Guide |
|---|---|---|---|
| Gemini 3.1 Pro | 2,000,000 | ~1,500,000 | Details |
| GPT-5.5 | 922,000 | ~690,000 | Details |
| GPT-4.1 | 1,000,000 | ~750,000 | Details |
| Gemini 3.5 Flash | 1,000,000 | ~760,000 | Details |
| Claude Fable 5 | 1,000,000 | ~750,000 | Details |
| Claude Opus 4.8 | 1,000,000 | ~750,000 | Details |
| Claude Sonnet 4.6 | 1,000,000 | ~750,000 | Details |
| o3 / o4-mini | 200,000 | ~150,000 | Details |
| GPT-4o | 128,000 | ~96,000 | Details |
| Grok 4.3 | 1,000,000 | ~750,000 | Details |
Who these tools are for
Developers
Estimate API costs before shipping. Check if your system prompt plus user input fits the context window. Compare pricing across providers without clicking through 5 different docs.
Prompt Engineers
Tune prompt length without burning API credits. See which model tier your prompt needs. Check if you can downgrade to cheaper tiers without hitting the ceiling.
Researchers & Writers
Figure out if your 200-page document will fit in one prompt. Decide between ChatGPT, Claude, and Gemini for long-form analysis based on real context limits.