LightOnOCR-1B is a novel vision-language model for Optical Character Recognition (OCR) that delivers state-of-the-art performance in its weight class, surpassing larger general-purpose models while maintaining efficiency by running significantly faster than competitors. Unlike many recent complex, non-trainable pipeline-based OCR models, LightOnOCR-1B is fully end-to-end trainable and fine-tunable for specific languages or domains, thanks to its diverse large-scale PDF training corpus. The model incorporates a vision transformer with a lean language backbone and achieves superior document understanding with high speed and low cost. It processes documents at a rate of 5.71 pages per second on a single H100 GPU, translating to less than $0.01 per 1,000 pages at current cloud pricing. The system offers variants with pruned vocabularies for additional speedup, particularly beneficial for European languages, while maintaining near-identical accuracy. LightOnOCR-1B's efficiency and adaptability make it a compelling choice for the OCR community, supporting easy integration into production and further specialization through fine-tuning, all while being open-source and integrated with vLLM for high-throughput serving.