Glossary
What is Context window?
The maximum amount of text an AI model can keep in mind at once, including your prompt, pasted files and the conversation so far.
Also written as context length, context limit.
The context window is the working memory of an AI model. Everything the model considers when it writes an answer has to fit inside it: your instructions, any documents you pasted, and the earlier messages in the same chat.
Why it matters for everyday use
When a conversation gets very long, or you paste in a huge document, the model may lose track of details from earlier on. You might notice it forgetting a fact you gave it at the start, repeating itself or drifting away from the tone you asked for. Newer models have much larger context windows than older ones, but there is always some limit.
Practical tips
- For a new task, start a fresh chat instead of continuing an old, long one.
- Put the most important instructions and facts in your prompt clearly, rather than spread across many messages.
- If an answer starts to drift, paste your best prompt again in a new chat.
- For very large collections of documents, businesses often use an approach called RAG, which fetches only the relevant pieces and feeds those to the model.
