How we chunk long-form content and maintain translation quality with Claude API
When we launched LectuLibre, our AI-powered book translation platform, we thought the hard part would be fine-tuning translation quality. It turned out the real engineering challenge was more mundane: Claude's token limits.
A 300-page novel contains roughly 120,000 tokens. Claude 3 Sonnet has a 200K context window, so you might assume you can just send the whole book and ask for a translation. But the output token limit is only 4,096 tokens (8,192 for some models). Even if the input fits, asking for a 120,000-token translation in one call will hit a wall. The API will return a truncated response or an error.
In this post, I'll walk through the chunking and orchestration system we built to translate long-form content with Claude reliably and cost-effectively, without losing narrative consistency.
The core problem: input fits, output doesn't
