Context Window
The context window is the information the model can use for the current turn.
Messages, files, instructions, retrieved material and tool results can all occupy this working space.
Fill a demo context window
This demo uses a 100,000-token window simply to make the idea visible.
Context used8,000 / 100,000 tokens
Current message · 8k
Over capacity in this demo. A product now has to omit, truncate, summarise or selectively retrieve some material. The exact strategy depends on the product.
Can be inside the current context
✓
Relevant messages from this conversation.
✓
Files or retrieved text included for this turn.
✓
System instructions and tool results.
Not automatically the same thing
–
Every past chat you have ever had.
–
Every file or email in your accounts.
–
Permanent memory about you.
Key insight: context is the model's current working information. Memory is a mechanism for deciding what should persist and be brought back later.
Context Window · Go deeper
There is often more in context than the chat transcript you can see.
Visible chat, hidden instructions, retrieved material and tool results can all compete for the same capacity.
What is in the window?
Capacity is a hard limit, not a universal quality gauge
Move the slider. The useful question is how much room remains and what the product will do if the selected context exceeds capacity.
Fresh chat can remove irrelevant history
Start a new conversation when the task changes, then carry forward the brief, decisions and sources that still matter.
Memory can reintroduce selected information
Memory or retrieval can place relevant past information back into a future context window.