# Context Truncation

> Removing or clipping older or excess input when a prompt grows beyond the model's context limit.

- Category: Context & Memory
- Stage: Established
- Also called: Truncation, Dropped context, Context editing
- Canonical: https://www.joelcsaji.com/ai-dictionary/context-truncation

## Plain English

When the workspace is too full, some information gets left out.

## Example

A long chat loses early project constraints unless the app summarizes or retrieves them again.

## Why it matters

Users often assume the model remembers everything; truncation is one reason long conversations fail quietly.

## Related

- [Context Window](https://www.joelcsaji.com/ai-dictionary/context-window)
- [Compaction](https://www.joelcsaji.com/ai-dictionary/compaction)
- [Memory](https://www.joelcsaji.com/ai-dictionary/memory)

## Sources

- [OpenAI: Advanced Text Generation](https://platform.openai.com/docs/guides/text-generation/parameter-details)
- [Google Cloud Generative AI Glossary](https://docs.cloud.google.com/docs/generative-ai/glossary)
- [Anthropic: Context Editing](https://platform.claude.com/docs/en/build-with-claude/context-editing)