Context Window Explorer

Visualize and understand Claude's massive 200K token context

⏱ 75 min · ⚡ 240 XP · 📚 Module 1

What Is a Context Window?

The context window is the total amount of text an AI can "see" at once — including your prompt, system instructions, conversation history, and the response. Think of it as the model's working memory. Claude's 200K token window means it can process roughly 500 pages of text in a single conversation.

Model Comparison

See how Claude stacks up against other models:

Claude 4.6

200K tokens (up to 1M with extended context)

GPT-4o

128K tokens

Gemini 2.x

1M tokens

Key insight: Claude Opus 4.6 can match Gemini's 1M window with extended context. Even at the standard 200K, Claude's context is often more effectively utilized — Claude shows stronger recall and reasoning across its full context compared to models that may "lose" information in the middle of long contexts (the "lost in the middle" phenomenon).

Live Token Counter

Type or paste text below to see tokens fill up in real-time. Try different content types to see how they tokenize differently.

0 tokens 200,000 tokens

Est. Tokens

Characters

Chars per Token

Token Density by Content Type

Different types of content tokenize very differently. Code tends to use more tokens per character due to special characters and indentation, while prose is more efficient.

English Prose~4 characters per token

~4:1

Python Code~3.5 characters per token

~3.5:1

JSON Data~3 characters per token

~3:1

HTML/XML~2.5 characters per token

~2.5:1

Non-English Text~2 characters per token

~2:1

What Fits in 200K Tokens?

To put Claude's context window in perspective:

📚

~500 Pages

of a novel

💻

~150K Lines

of code

📄

~300 PDFs

typical business docs

💬

~8 Hours

of conversation

Match Content Type to Token Density

Tap one on the left, then its match on the right

Context Window — Console

⚡Write a prompt

Write a prompt optimized for context window efficiency. You have a 50-page document to analyze but only care about 3 specific things. Tell Claude exactly what to focus on, what to skip, and how to present findings concisely.

▸

Type a prompt below to get started.

Try: