chandra-ocr-2
by datalab-to
High-accuracy multilingual OCR with 90+ language support
datalab-to/chandra-ocr-2mixpeek://image_extractor@v1/datalab_chandra_ocr2_v1Overview
Chandra OCR 2 from Datalab is a 5B parameter vision-language model optimized for optical character recognition across 90+ languages. Built on the Qwen3.5 architecture, it achieves 85.9% on the olmOCR benchmark (SOTA at time of release) and 77.8% multilingual accuracy across 43 languages, a 12-point improvement over v1. The model outputs structured Markdown, HTML, or JSON and excels at handwriting, tables, and mathematical formulas.
Architecture
Image-text-to-text model based on Qwen3.5 with a vision encoder fine-tuned for document understanding. Processes full-page document images and generates structured text output (Markdown with table formatting and LaTeX math). The dual-encoder architecture handles both the visual layout and text content simultaneously.
Mixpeek SDK Integration
// No extractor parameter takes a Hugging Face model id (checked against
// GET /v1/discovery/extractors, which returns 13), so chandra-ocr-2 runs
// on your side and the output is upserted through POST
// /v1/namespaces/{namespace_id}/documents/upsert. On Enterprise the other
// path is to upload the weights instead: POST /v1/namespaces/{id}/models
// accepts the huggingface format and a custom plugin loads them.
const res = await fetch(
"https://api.mixpeek.com/v1/namespaces/ns_your_namespace/documents/upsert",
{
method: "POST",
headers: {
Authorization: "Bearer API_KEY",
"Content-Type": "application/json",
},
body: JSON.stringify({
collection_id: "col_your_collection",
documents: [
{
document_id: "asset-00412",
// The model produces text, so it lands in payload. Give the
// collection a text vector index and embed that text to make it
// searchable rather than only filterable.
payload: { extracted_text: modelOutput, source_key: "archive/2026/asset-00412" },
vectors: { "image-embedding": embeddingOfModelOutput },
},
],
}),
},
);
// Managed alternative, if this exact model is not the requirement:
// image_extractor@v1 runs google/siglip-base-patch16-224
// (768-d) over a bucket, with no inference of your own.Capabilities
- 90+ language OCR
- Handwriting recognition
- Table structure extraction
- Mathematical formula recognition
- Markdown/HTML/JSON output
Use Cases on Mixpeek
Benchmarks
| Dataset | Metric | Score | Source |
|---|---|---|---|
| olmOCR | Accuracy | 85.9% | Model card |
| Multilingual (43 langs) | Accuracy | 77.8% | Model card |
| Table Recognition | TEDS | 92.1% | Model card |
Performance
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Specification
Research Paper
Model paper or technical report
arxiv.orgBuild a pipeline with chandra-ocr-2
Add this model to a processing pipeline alongside other extractors. Combine with retrieval stages for end-to-end search.
Run it on your own data, free