Watch a chat fill up.

Every AI conversation lives inside a window. See tokens pile up, watch old messages fall out, and learn the trick that keeps long chats sharp.

demo window

The window39 / 2,000 tok · 2%

Press Demo and watch a bakery brand plan a Diwali launch until the window overflows.
Then press With compaction and compare the ending.

The bill

Rs 0.00

whole chat · 0 turns · Claude Sonnet 5

Every turn re-sends the whole window. Long chats get pricier per message. This demo window is 2,000 tokens; real Sonnet carries 200k, about 100× more.

prices are approximate list rates, August 2026·Rs at 95/$·token counts estimated

01 · Tokens

Everything costs.

Every word you send, and every word it replies, is tokens. Every turn re-sends the whole window, so the meter climbs faster as the chat grows.

02 · The cliff

Old messages vanish.

When the window fills, the oldest messages fall out. The model never announces it. Run the demo to the end and ask it about the price.

03 · Compaction

A summary buys room.

Compacting folds old messages into a short summary. Space comes back, detail quietly drops. Claude and ChatGPT do this behind the scenes.