Baidu open-sources Unlimited OCR 2 and MarathonDocBench under MIT licence

Baidu has open-sourced Unlimited OCR 2, a 3-billion-parameter multimodal vision-language model specialised for document layout analysis, structured table extraction and text recognition across extended document lengths. Checkpoints and source code are published on GitHub and Hugging Face under the MIT licence for unrestricted research and commercial deployment.

The model introduces Shifted Recursive Sliding Window Attention (SR-SWA), which reduces computational complexity from quadratic to linear relative to document length. The attention mechanism enables the model to parse continuous document scans spanning hundreds of pages without truncation or loss of global structural context across sections.

Alongside the model weights, Baidu released MarathonDocBench, an evaluation benchmark tailored for ultra-long multi-page financial reports, legal filings and technical manuals. The benchmark tests extraction fidelity across complex cross-page tables, nested hierarchies and multi-column document structures, demonstrating significant accuracy improvements over standard sliding-window OCR architectures.