Claude 4 "Maximum Token" Error in Long Documents

Claude 4 models have a 200,000-token context window, but output is limited per response. If your document exceeds the single-response output capacity, Claude returns a maximum token error. Break the document into sections and process each separately, or use the API with higher max_tokens settings.

In Claude.ai, you cannot directly increase the output token limit per response. For longer outputs, use the API where you can set max_tokens up to the model’s output limit (8,192 tokens for most Claude 4 models, 64,000 for Claude Sonnet 4.5 Extended).

The 200,000-token context window is the maximum input Claude can read at once. The output token limit is separate and much smaller - it caps how much Claude can generate in a single response, not how much it can read.

Split your document into logical sections - chapters, sections, or functional modules - and process them one at a time. Ask Claude to summarise each section before proceeding to maintain continuity across responses.

Use chunked prompting: divide the task into phases (outline, draft, expand, refine) and process each phase in a separate message. This avoids single-response output limits while keeping the full context in Claude’s memory within the same conversation.

Yes. Via the Anthropic API, you can set max_tokens to control output length per call. For Claude Sonnet 4.5, you can access extended output up to 64,000 tokens per response using the interleaved thinking beta feature.

The maximum token error means Claude has reached its per-response output limit for that session type. It is not a bug - it is a hard architectural limit. The solution is to continue the task in a follow-up message or restructure the prompt to request shorter outputs.