Post by Extend

OpenAI recently released GPT 5.5. We evaluated the model on document splitting using Extend’s splitter harness, comparing raw model performance against performance on Extend’s platform. In our benchmark, GPT 5.5 showed a major improvement over GPT 5.4 in accuracy: Raw model: GPT 5.4: 51.42% GPT 5.5: 72.03% On Extend's platform: GPT 5.4: 76.75% GPT 5.5: 81.72% The results point to two things: 1/ GPT 5.5 is a significant step forward for document understanding. 2/ model quality is only one part of production document processing. Accurate splitting also depends on the system around the model: chunking strategy, context management, boundary detection, validation, and evaluation. As models improve, the platform layer becomes even more important. It’s what turns stronger model capabilities into reliable production workflows.