### Answer The available documentation does not specify the maximum character limit for a knowledge base chunk in Retell AI. [(1) ]() However, there is a mention of a 4,000-character limit for function call responses (not knowledge base chunks specifically) . [(2) ]() For knowledge base best practices, the documentation recommends: - Keep each

##

section focused and reasonably short [(1) ]() - If a

##

section becomes long, split it into multiple `##`/`###` sections - Write short paragraphs and lists to separate concepts; avoid walls of text If you need the exact chunk size limit for knowledge bases, I'd recommend reaching out to Retell support directly or checking: - [Knowledge Base Documentation]() - [Contact Sales]() Would you like me to provide a general answer based on typical RAG chunking practices?

​ To learn more, see the sources I considered: [[1] Knowledge Base](https://docs.retellai.com/build/knowledge-base) [[2] Increase function result character limit](https://discord.com/channels/1186424376300679209/1379544272096854177) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer The custom function reply response limit is 15,000 characters. [(1) ]() This was increased from the previous 4,000-character limit as noted in the platform changelog improvements.

​ To learn more, see the sources I considered: [[1] Platform Changelogs | Retell AI](https://www.retellai.com/changelog) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.