The context window is 1M tokens.

The 1M (1 million) token context window refers to how much information Claude can "see" and work with in a single conversation. Here's what that means practically:

- Tokens are roughly chunks of text — about 3/4 of a word on average. So 1M tokens is roughly 750,000 words of text.

- This is the total space for the entire conversation: system instructions, your messages, my responses, tool outputs (file contents, command results), and everything else.

- A larger context window means I can read and reason about more code at once — large files, multiple files, lengthy diffs, etc. — without losing track of earlier context.

What it means for you in practice:

- I can handle longer conversations before context gets compressed/summarized

- I can read and work with very large files or many files simultaneously

- Complex, multi-step tasks across a big codebase are more feasible

It does not mean I permanently remember everything — once a conversation ends, that context is gone (unless saved to memory). And as the conversation grows very long, older messages may still get compressed to stay within limits.

⏺ A context window is essentially Claude's "working memory" for a single conversation — the maximum amount of text it can process at once.

Think of it like a desk:

- Everything in our conversation sits on this desk — your messages, my replies, file contents I read, command outputs, system instructions, etc.

- The desk has a fixed size (1M tokens in this case)

- Once the desk is full, older items get compressed or summarized to make room for new ones

Key points:

- It's temporary — when the conversation ends, the desk is cleared. Nothing carries over to the next conversation automatically (that's what the memory system is for).

- It's shared — both input and output count toward it. A huge file I read takes up space that could otherwise hold more conversation.

- Bigger is better — a larger context window means I can hold more information simultaneously, which helps with complex tasks that involve many files or long discussions.

Analogy: If you've ever had too many browser tabs open and your computer slows down — context window is similar. It's the limit on how much I can actively "have open" and reason about at the same time.