README.md

---
library_name: transformers
license: openrail
license_link: LICENSE
tags:
  - ocr
  - pdf
  - markdown
  - layout
---

<p align="center">
  <img src="datalab-logo.png" alt="Datalab Logo" width="150"/>
</p>

<h1 align="center">Datalab</h1>
<p align="center">
  <strong>State of the Art models for Document Intelligence</strong>
</p>
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</p>

<hr/>

# Surya

Surya is a 650M param OCR model with these features:

- Accuracy - scores 83.3% on [olmOCR-bench](https://huggingface.co/datasets/allenai/olmOCR-bench) (top under 3B params)
- Speed - throughput of 5 pages/s on an RTX 5090
- Multilingual - scores 87.2% on an internal benchmark set of 91 languages (more [here](#multilingual))
- Layout analysis (table, image, header, etc.) with reading order
- Table recognition (rows + columns)

It works on a range of documents (see [usage](#usage) and [benchmarks](#benchmarks)).

## Try Datalab's Managed Platform

Our managed platform runs both Surya, and variants of our highest accuracy model, [Chandra](https://github.com/datalab-to/chandra).

Get started with **$5 in free credits** — [sign up](https://www.datalab.to/?utm_source=gh-surya) (takes under 30 seconds) or try our free [public playground](https://www.datalab.to/playground?utm_source=gh-surya).

## Model Information

<img src="assets/olmocr_size_chart.png" width="700"/>


|                            Detection                             |                                   OCR                                   |
|:----------------------------------------------------------------:|:-----------------------------------------------------------------------:|
|  <img src="assets/excerpt.png" width="140"/>  |  <img src="assets/excerpt_text.png" width="140"/> |

|                               Layout                               |                       Table Recognition                       |
|:------------------------------------------------------------------:|:-------------------------------------------------------------:|
| <img src="assets/excerpt_layout.png" width="140"/> | <img src="assets/scanned_tablerec.png" width="140"/> |


Surya is named for the [Hindu sun god](https://en.wikipedia.org/wiki/Surya), who has universal vision.

## Examples

| Name              |              Detection              |                                       OCR |                                       Layout |                                          Order |                                       Table Rec |
|-------------------|:-----------------------------------:|------------------------------------------:|---------------------------------------------:|------------------------------------------------:|------------------------------------------------:|
| Newspaper         | [Image](assets/newspaper.png) | [Image](assets/newspaper_text.png) | [Image](assets/newspaper_layout.png) | [Image](assets/newspaper_reading.png) |                                                  |
| Textbook          | [Image](assets/textbook.png)  | [Image](assets/textbook_text.png)  | [Image](assets/textbook_layout.png)  | [Image](assets/textbook_reading.png)  |                                                  |
| Tax Form          | [Image](assets/form.png)      | [Image](assets/form_text.png)      | [Image](assets/form_layout.png)      | [Image](assets/form_reading.png)      | [Image](assets/form_tablerec.png)      |
| Handwritten Notes | [Image](assets/handwritten.png) | [Image](assets/handwritten_text.png) | [Image](assets/handwritten_layout.png) | [Image](assets/handwritten_reading.png) | [Image](assets/handwritten_tablerec.png) |
| Corporate Doc     | [Image](assets/corporate.png) | [Image](assets/corporate_text.png) | [Image](assets/corporate_layout.png) | [Image](assets/corporate_reading.png) | [Image](assets/corporate_tablerec.png) |

# Commercial usage

The Surya code is licensed under Apache 2.0. The model weights use a modified AI Pubs Open Rail-M license (free for research, personal use, and startups under $5M funding/revenue). For broader commercial licensing of the model weights, visit our pricing page [here](https://www.datalab.to/pricing?utm_source=gh-surya).

# Installation

Install with:

```shell
pip install surya-ocr
```

# Usage

Surya 2 runs layout, OCR, and table recognition through a single VLM served
by `vllm` (GPU) or `llama.cpp` (CPU / Apple Silicon). The inference manager
will spawn one for you on first use; you can also point it at an existing
server via `SURYA_INFERENCE_URL=http://host:port/v1`.

- Inspect the settings in `surya/settings.py`.  You can override any setting via env var (e.g. `SURYA_INFERENCE_BACKEND=vllm`).
- Text detection and OCR errors are separate models.

## Interactive App

I've included a streamlit app that lets you interactively try Surya on images or PDF files.  Run it with:

```shell
pip install streamlit pdftext
surya_gui
```

## OCR (text recognition)

This command will write out a json file with the detected text and bboxes:

```shell
surya_ocr DATA_PATH
```

- `DATA_PATH` can be an image, pdf, or folder of images/pdfs
- `--images` will save images of the pages and detected blocks (optional)
- `--output_dir` specifies the directory to save results to instead of the default
- `--page_range` specifies the page range to process in the PDF, specified as a single number, a comma separated list, a range, or comma separated ranges - example: `0,5-10,20`.

The `results.json` file contains a dict keyed by input filename (no extension). Each value is a list of page dicts. Each page dict contains:

- `blocks` - per-block OCR results in reading order
  - `label` - canonicalized layout label (e.g. `Text`, `SectionHeader`, `Table`, `Equation`, `Picture`, `Form`, `PageHeader`, ...). See `surya/layout/label.py:LAYOUT_PRED_RELABEL` for the full canonical-name set.
  - `raw_label` - original label emitted by the model, before canonicalization
  - `reading_order` - 0-indexed position in layout output
  - `html` - block content as HTML (math wrapped in `<math>...</math>`, tables as `<table>...</table>`, etc.). `""` if the block was skipped
  - `polygon` - 4-corner polygon in `[[x0,y0],[x1,y0],[x1,y1],[x0,y1]]` order
  - `bbox` - axis-aligned `[x0, y0, x1, y1]` derived from the polygon
  - `confidence` - mean per-token probability across the block's decode (0-1)
  - `skipped` - true if the block was a visual label (e.g. Picture) and not OCR'd
  - `error` - true if the block OCR call failed
- `image_bbox` - `[0, 0, width, height]` for the page image

**Performance tips**

Throughput is governed by the inference backend, not a `RECOGNITION_BATCH_SIZE` env var. With `vllm`, raise `--max-num-seqs` / `--max-num-batched-tokens` (or `SURYA_INFERENCE_PARALLEL` on the client side) to keep more pages in flight. With `llama.cpp`, set `SURYA_INFERENCE_PARALLEL` to match `--parallel` on `llama-server`.

### From python

```python
from PIL import Image
from surya.inference import SuryaInferenceManager
from surya.recognition import RecognitionPredictor

manager = SuryaInferenceManager()
recognition_predictor = RecognitionPredictor(manager)

# Default: full-page OCR. One VLM call per page; returns layout + content as
# HTML <div data-bbox=... data-label=...> blocks.
predictions = recognition_predictor([Image.open(IMAGE_PATH)])

# Block mode: pre-run layout, then per-block OCR. Auto-selected when
# `layout_results` is passed.
from surya.layout import LayoutPredictor
layout = LayoutPredictor(manager)
layouts = layout([Image.open(IMAGE_PATH)])
predictions = recognition_predictor([Image.open(IMAGE_PATH)], layouts)
```


## Text line detection

This command will write out a json file with the detected bboxes.

```shell
surya_detect DATA_PATH
```

- `DATA_PATH` can be an image, pdf, or folder of images/pdfs
- `--images` will save images of the pages and detected text lines (optional)
- `--output_dir` specifies the directory to save results to instead of the default
- `--page_range` specifies the page range to process in the PDF, specified as a single number, a comma separated list, a range, or comma separated ranges - example: `0,5-10,20`.

The `results.json` file will contain a json dictionary where the keys are the input filenames without extensions.  Each value will be a list of dictionaries, one per page of the input document.  Each page dictionary contains:

- `bboxes` - detected bounding boxes for text
  - `bbox` - the axis-aligned rectangle for the text line in (x1, y1, x2, y2) format.  (x1, y1) is the top left corner, and (x2, y2) is the bottom right corner.
  - `polygon` - the polygon for the text line in (x1, y1), (x2, y2), (x3, y3), (x4, y4) format.  The points are in clockwise order from the top left.
  - `confidence` - the confidence of the model in the detected text (0-1)
- `vertical_lines` - vertical lines detected in the document
  - `bbox` - the axis-aligned line coordinates.
- `page` - the page number in the file
- `image_bbox` - the bbox for the image in (x1, y1, x2, y2) format.  (x1, y1) is the top left corner, and (x2, y2) is the bottom right corner.  All line bboxes will be contained within this bbox.

**Performance tips**

Detection is a torch model. `DETECTOR_BATCH_SIZE` defaults to an auto-picked value at runtime; override the env var to control VRAM usage on GPU and raise it on larger cards.

### From python

```python
from PIL import Image
from surya.detection import DetectionPredictor

det_predictor = DetectionPredictor()
predictions = det_predictor([Image.open(IMAGE_PATH)])
```

## Layout and reading order

This command will write out a json file with the detected layout and reading order.

```shell
surya_layout DATA_PATH
```

- `DATA_PATH` can be an image, pdf, or folder of images/pdfs
- `--images` will save images of the pages and detected text lines (optional)
- `--output_dir` specifies the directory to save results to instead of the default
- `--page_range` specifies the page range to process in the PDF, specified as a single number, a comma separated list, a range, or comma separated ranges - example: `0,5-10,20`.

The `results.json` file contains a dict keyed by input filename (no extension). Each value is a list of page dicts. Each page dict contains:

- `bboxes` - layout boxes in reading order
  - `polygon` - 4-corner polygon `[[x0,y0],[x1,y0],[x1,y1],[x0,y1]]`
  - `bbox` - axis-aligned `[x0, y0, x1, y1]` derived from the polygon
  - `label` - canonicalized label. One of `Caption`, `Footnote`, `Equation`, `ListGroup`, `PageHeader`, `PageFooter`, `Picture`, `SectionHeader`, `Table`, `Text`, `Figure`, `Code`, `Form`, `TableOfContents`, `ChemicalBlock`, `Diagram`, `Bibliography`, `BlankPage`
  - `raw_label` - original label emitted by the model
  - `position` - 0-indexed reading order
  - `count` - model's token estimate for OCR'ing this block (rounded to multiples of 50; used to size the per-block decode budget)
  - `confidence` - mean per-token probability across the layout decode (0-1)
- `image_bbox` - `[0, 0, width, height]`
- `raw` - raw JSON the layout model emitted, for debugging
- `error` - true if the layout call failed

**Performance tips**

Layout runs through the shared inference backend. Throughput tuning is the same as OCR — see Performance tips above.

### From python

```python
from PIL import Image
from surya.inference import SuryaInferenceManager
from surya.layout import LayoutPredictor

layout_predictor = LayoutPredictor(SuryaInferenceManager())
layout_predictions = layout_predictor([Image.open(IMAGE_PATH)])
```

## Table Recognition

This command will write out a json file with the detected table cells and row/column ids, along with row/column bounding boxes.  If you want to get cell positions and text, along with nice formatting, check out the [marker](https://github.com/datalab-to/marker) repo.  You can use the `TableConverter` to detect and extract tables in images and PDFs.  It supports output in json (with bboxes), markdown, and html.

```shell
surya_table DATA_PATH
```

- `DATA_PATH` can be an image, pdf, or folder of images/pdfs
- `--images` will save annotated row + column overlays alongside the json (optional)
- `--output_dir` specifies the directory to save results to instead of the default
- `--page_range` specifies the page range to process in the PDF, specified as a single number, a comma separated list, a range, or comma separated ranges - example: `0,5-10,20`.
- `--skip_table_detection` tells table recognition not to detect tables first.  Use this if your image is already cropped to a table.

The `results.json` file contains a dict keyed by input filename (no extension). Each value is a list of per-table dicts. Each table dict contains:

- `rows` - detected table rows in reading order
  - `polygon` / `bbox` - row geometry (same convention as everywhere else)
  - `row_id` - 0-indexed row id
- `cols` - detected table columns
  - `polygon` / `bbox` - column geometry
  - `col_id` - 0-indexed column id
- `cells` - geometric row × column intersections (simple mode)
  - `polygon` / `bbox` - cell geometry
  - `row_id`, `col_id`, `cell_id`
- `html` - full `<table>...</table>` HTML (only populated when `predict_full` is used; handles spanning cells / header rows). `null` in simple mode.
- `mode` - `"simple"` or `"full"`
- `image_bbox` - the table crop bbox
- `error` - true if the table_rec call failed
- `raw` - raw model output, for debugging

**Performance tips**

Table recognition routes through the shared VLM. Throughput tuning is the same as OCR.

### From python

```python
from PIL import Image
from surya.inference import SuryaInferenceManager
from surya.table_rec import TableRecPredictor

table_rec_predictor = TableRecPredictor(SuryaInferenceManager())

# Default: rows + columns only, cells derived from intersections.
table_predictions = table_rec_predictor([Image.open(IMAGE_PATH)])

# Or full HTML output (better for spanning cells / headers):
# table_predictions = table_rec_predictor.predict_full([image])
```

## Math / equations

Surya 2 handles math inline as part of full-page OCR — recognized equations
come back inside `<math>...</math>` tags in the same HTML output as
surrounding prose, in KaTeX-compatible LaTeX. No separate LaTeX OCR pass.

# Inference Backends

Layout / OCR / table_rec all share one VLM, served either by `vllm` (GPU) or `llama.cpp` (CPU / Apple Silicon). The `SuryaInferenceManager` will spawn one automatically; you can also point at a pre-running server:

```bash
# Attach to an existing vllm
export SURYA_INFERENCE_BACKEND=vllm
export SURYA_INFERENCE_URL=http://localhost:8000/v1
```

| Setting                           | Default                           | Notes                                                  |
|-----------------------------------|-----------------------------------|--------------------------------------------------------|
| `SURYA_INFERENCE_BACKEND`         | auto (vllm if NVIDIA, else llamacpp) | `vllm` \| `llamacpp` \| unset (auto)                |
| `SURYA_INFERENCE_URL`             | (auto-spawn)                      | Attach to a running OpenAI-compatible server          |
| `SURYA_INFERENCE_PARALLEL`        | 8                                 | Client-side concurrency to the backend                |
| `SURYA_GUIDED_LAYOUT`             | true                              | JSON-schema-constrained layout decode                 |

# Limitations

- This is specialized for document OCR. Performance on photos or natural scenes is not the goal.
- Layout / OCR / table_rec all need a running inference backend (vllm or llama.cpp). Detection runs purely on torch and works without it.

## Troubleshooting

If OCR isn't working properly:

- Try increasing resolution of the image so the text is bigger.  If the resolution is already very high, try decreasing it to no more than a `2048px` width.
- Preprocessing the image (binarizing, deskewing, etc) can help with very old/blurry images.
- You can adjust `DETECTOR_BLANK_THRESHOLD` and `DETECTOR_TEXT_THRESHOLD` if you don't get good results.  `DETECTOR_BLANK_THRESHOLD` controls the space between lines - any prediction below this number will be considered blank space.  `DETECTOR_TEXT_THRESHOLD` controls how text is joined - any number above this is considered text.  `DETECTOR_TEXT_THRESHOLD` should always be higher than `DETECTOR_BLANK_THRESHOLD`, and both should be in the 0-1 range.  Looking at the heatmap from the debug output of the detector can tell you how to adjust these (if you see faint things that look like boxes, lower the thresholds, and if you see bboxes being joined together, raise the thresholds).

# Manual install

If you want to develop surya, you can install it manually with [uv](https://docs.astral.sh/uv/):

```bash
git clone https://github.com/datalab-to/surya.git
cd surya
uv sync --group dev      # installs runtime + dev deps
uv run surya_ocr ...     # or `uv shell` to enter the venv
```

# Benchmarks

Surya 2 is a single VLM that handles layout analysis, OCR (full-page or
per-block), and table recognition in one model. We evaluate end-to-end on
[olmOCR-bench](https://huggingface.co/datasets/allenai/olmOCR-bench) — the
standard quality benchmark for document parsers.

## olmOCR-bench

Pareto-optimal, and best in class under 3B params.

| Model                       | Params    | Score    |
|-----------------------------|----------:|---------:|
| Infinity-Parser2-Pro        |     35.1B |     87.6 |
| Chandra OCR 2 (Datalab)     |      5.3B |     85.9 |
| dots.mocr                   |      3.0B |     83.9 |
| **Surya OCR 2** (Datalab)   | **0.65B** | **83.3** |
| LightOnOCR 2-1B \*          |      1.0B |     83.2 |
| Chandra OCR 1 (Datalab)     |      9.0B |     83.1 |
| olmOCR (anchored)           |      8.3B |     77.4 |
| GOT OCR                     |      0.6B |     48.3 |

\* **LightOnOCR 2-1B** uses a different benchmark methodology than the other entries (see their [release notes](https://huggingface.co/lightonai/LightOnOCR-2-1B)); the score is included for context but is not directly comparable.

Comparison scores from the [olmOCR-bench dataset card](https://huggingface.co/datasets/allenai/olmOCR-bench).

Surya 2, per-source pass rate on the `default` preset (8,413 tests total):

| ArXiv | Base | Hdr/Ftr | TinyTxt | MultCol | OldScan | OldMath | Tables |
|------:|-----:|--------:|--------:|--------:|--------:|--------:|-------:|
|  88.3 | 99.7 |    92.5 |    93.7 |    82.4 |    41.8 |    81.4 |   86.6 |

## Multilingual

We also evaluate Surya 2 against a 91-language internal benchmark covering
text accuracy, layout, tables, math, and reading order in documents drawn
from each language.

**Overall pass rate: 87.2% across 91 languages.** 38 of the
91 languages score ≥ 90%; 76 score ≥ 80%.

Top 15 widely-spoken languages:

| Code | Language    | Score |
|------|-------------|------:|
| `ar` | Arabic      | 72.7% |
| `bn` | Bengali     | 82.7% |
| `zh` | Chinese     | 82.5% |
| `en` | English     | 92.3% |
| `fr` | French      | 89.3% |
| `de` | German      | 89.7% |
| `hi` | Hindi       | 82.2% |
| `it` | Italian     | 93.0% |
| `ja` | Japanese    | 86.2% |
| `ko` | Korean      | 86.7% |
| `fa` | Persian     | 82.3% |
| `pt` | Portuguese  | 86.1% |
| `ru` | Russian     | 88.8% |
| `es` | Spanish     | 90.7% |
| `vi` | Vietnamese  | 73.2% |

See [https://github.com/datalab-to/surya/blob/master/static/docs/multilingual.md](https://github.com/datalab-to/surya/blob/master/static/docs/multilingual.md) for the full 91-language table.

## Throughput

Full-page OCR, 96 DPI input (~2,400 output tokens/page average), measured
client-side against a running inference server.

### RTX 5090 (vllm)

`vllm/vllm-openai:v0.20.1`, single RTX 5090 (32 GB).

| Concurrency | Pages/s |  Tokens/s | p50 (ms) | p95 (ms) | avg tok/page |
|------------:|--------:|----------:|---:|---:|---:|
|         128 |    5.35 |    12,884 | 18,915 | 42,538 | 2,410 |

### Apple Silicon (llama.cpp / Metal)

`llama-server` with Metal backend.

| `--parallel` |  Pages/s | Tokens/s | p50 (ms) | p95 (ms) | avg tok/page | Power |
|-------------:|---------:|---------:|---:|---:|---:|---:|
|            8 |    0.108 |      254 | 59,313 | 129,173 | 2,360 | ~30 W |

## Reproducing

We score Surya 2 on olmOCR-bench by serving the model with `vllm` (or
`llama.cpp`) and running the olmOCR-bench harness from
[allenai/olmocr](https://github.com/allenai/olmocr), with some adjustments applied to account for our output HTML format.

# Training

Layout, OCR, and table recognition all share a single vision-language model
(Qwen3.5-style architecture, ~650M params). It's trained on diverse document
images to emit either a layout JSON or a full-page HTML output, depending on
prompt. Text-line detection is a separate small torch model — a modified
EfficientViT segformer trained from scratch on document line annotations.

If you want help finetuning Surya on your own data, or to use our managed
training stack, reach us at hi@datalab.to.

# Thanks

This work would not have been possible without amazing open source AI work:

- [Qwen3-VL](https://huggingface.co/Qwen) from Alibaba
- [vllm](https://github.com/vllm-project/vllm) and [llama.cpp](https://github.com/ggerganov/llama.cpp) for inference
- [Segformer](https://arxiv.org/pdf/2105.15203.pdf) from NVIDIA
- [EfficientViT](https://github.com/mit-han-lab/efficientvit) from MIT
- [timm](https://github.com/huggingface/pytorch-image-models) from Ross Wightman
- [transformers](https://github.com/huggingface/transformers) from huggingface
- [CRAFT](https://github.com/clovaai/CRAFT-pytorch), a great scene text detection model

Thank you to everyone who makes open source AI possible.

# Citation

If you use surya (or the associated models) in your work or research, please consider citing us using the following BibTeX entry:

```bibtex
@misc{paruchuri2025surya,
  author       = {Vikas Paruchuri and Datalab Team},
  title        = {Surya: A lightweight document OCR and analysis toolkit},
  year         = {2025},
  howpublished = {\url{https://github.com/datalab-to/surya}},
  note         = {GitHub repository},
}