Guide
How much can you paste into ChatGPT?
On current models, roughly 787,000 English words — ChatGPT now runs GPT-6 (Sol on paid plans, Luna on Free and Go), and the GPT-6 family's API context window is 1,050,000 tokens, about 787,500 words. Older GPT-5 conversations topped out around 400,000 tokens, about 300,000 words.
The practical limit is lower
Three things shrink the advertised window: the conversation history counts too (every previous message is re-read each turn), the model's answer needs room (reserve 10–20% for output), and accuracy degrades in the middle of very long contexts. A good rule: keep a single conversation under half the window, and start a fresh chat — with a summary of what mattered — once you pass it.
Measure any paste first with the token counter — it shows the share of each model's window your text uses.