opendataloader-bench

1. About the Project

PDF documents are everywhere, but LLMs can't read them directly. Extracting structured content — headings, tables, reading order — from PDFs is essential for RAG pipelines and document processing workflows.

This benchmark evaluates document structure and layout analysis engines to help you choose the right tool.

What we measure:

• Reading Order — Is the text extracted in the correct sequence?
• Table Fidelity — Are tables accurately reconstructed?
• Heading Hierarchy — Is the document structure preserved?

The evaluation pipeline is modular—add new engines, corpora, or metrics with minimal effort.

2. Benchmark Results

Quality Comparison

Engine	Overall	Reading Order	Table	Heading	Speed (s/page)	License
opendataloader [hybrid]	0.907	0.934	0.928	0.821	0.463	Apache-2.0
nutrient	0.885	0.925	0.708	0.819	0.008	Commercial
docling	0.882	0.898	0.887	0.824	0.762	MIT
marker	0.861	0.890	0.808	0.796	53.932	GPL-3.0
unstructured [hi_res]	0.841	0.904	0.588	0.749	3.008	Apache-2.0
edgeparse	0.837	0.894	0.717	0.706	0.036	Apache-2.0
opendataloader	0.831	0.902	0.489	0.739	0.015	Apache-2.0
mineru	0.831	0.857	0.873	0.743	5.962	AGPL-3.0
pymupdf4llm	0.732	0.885	0.401	0.412	0.091	AGPL-3.0
unstructured	0.686	0.882	0.000	0.388	0.077	Apache-2.0
markitdown	0.589	0.844	0.273	0.000	0.114	MIT
liteparse	0.576	0.866	0.000	0.000	1.061	Apache-2.0

Scores are normalized to [0, 1]. Higher is better for accuracy metrics; lower is better for speed. Bold indicates best performance.

Visual Comparison

Detailed JSON outputs live alongside each engine and capture the exact metric values:

• prediction/opendataloader/evaluation.json
• prediction/opendataloader-hybrid/evaluation.json
• prediction/docling/evaluation.json
• prediction/marker/evaluation.json
• prediction/edgeparse/evaluation.json
• prediction/nutrient/evaluation.json
• prediction/mineru/evaluation.json
• prediction/pymupdf4llm/evaluation.json
• prediction/unstructured/evaluation.json
• prediction/unstructured-hires/evaluation.json
• prediction/markitdown/evaluation.json
• prediction/liteparse/evaluation.json

3. Metrics

All scores are normalised to the [0, 1] range, where higher indicates a closer match to ground truth. Documents missing the artefacts required by a given metric yield null in per-document results and are excluded from aggregate means.

3.1. Reading Order Similarity (NID, NID-S)

The reading order is evaluated using Normalized Indel Distance (NID), which measures the similarity between the ground truth and predicted text.

$$NID = 1 - \frac{\text{distance}}{\text{len(gt)} + \text{len(pred)}}$$

• NID: Compares the full extracted text of the prediction against the ground truth.
• NID-S: Strips tables before comparison to focus on narrative reading order.

3.2. Table Structure Similarity (TEDS, TEDS-S)

Tables are evaluated using Tree Edit Distance Similarity (TEDS), comparing DOM structures with the APTED algorithm.

$${TEDS}(T_{\text{gt}}, T_{\text{pred}}) = 1 - \frac{{EditDist}(T_{\text{gt}}, T_{\text{pred}})}{\max(|T_{\text{gt}}|, |T_{\text{pred}}|, 1)}$$

• TEDS: Evaluates both structure and cell text.
• TEDS-S: Structure-only, ignoring textual differences (e.g., OCR noise).

3.3. Heading-Level Similarity (MHS, MHS-S)

Headings are parsed into a flat list and compared using APTED.

$${MHS}(H_{\text{gt}}, H_{\text{pred}}) = 1 - \frac{{EditDist}(H_{\text{gt}}, H_{\text{pred}})}{\max(|H_{\text{gt}}|, |H_{\text{pred}}|, 1)}$$

• MHS: Rewards correctly positioned headings and aligned content blocks.
• MHS-S: Structure-only, isolating heading topology.

3.4. References

• Z. Chen et al. "MDEval: Evaluating and Enhancing Markdown Awareness in Large Language Models." arXiv:2501.15000, 2025.
• X. Zhong et al. "Image-based Table Recognition: Data, Model, and Evaluation." ECCV Workshops, 2020.
• M. Pawlik and N. Augsten. "RTED: A Robust Algorithm for the Tree Edit Distance." arXiv:1201.0230, 2011.
• Upstage AI. "Document Parsing Benchmark (DP-Bench)." Hugging Face, 2024.

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4. Reproduce the Benchmark

Want to run this benchmark yourself or add a new engine? Follow the steps below.

Prerequisites

• Python 3.13 or higher
• Git LFS (for PDF files)

Installation

1. Clone and set up Git LFS:

   git clone https://github.com/opendataloader-project/opendataloader-bench
   cd opendataloader-bench
   git lfs install
   git lfs pull
   

2. Install base dependencies (evaluation + chart generation only):

   uv sync
   

3. Install engine(s) you want to run:

   # Individual engines
   uv sync --extra opendataloader
   uv sync --extra docling
   uv sync --extra markitdown
   
   # All permissively-licensed engines at once
   uv sync --extra all-safe
   

   AGPL/GPL engines (marker, MinerU, PyMuPDF) and commercial engines (nutrient) are not runnable from this repo — their parser code has been removed to avoid license/commercial-tier entanglement. Their prediction/ results are preserved so the comparison charts still display them.

   Don't have uv? See installation guide

Running the Benchmark

Quality Benchmark (default)

# Full pipeline: parse → evaluate → archive → chart
uv run src/run.py

# Single engine (skips engines that already have evaluation.json)
uv run src/run.py --engine docling

# Force re-run even if results exist
uv run src/run.py --engine docling --force

Individual Stages

# 1. Parse PDFs
uv run src/pdf_parser.py

# 2. Evaluate predictions
uv run src/evaluator.py

# 3. Generate charts (works with existing evaluation.json data only)
uv run src/generate_benchmark_chart.py

# 4. Archive results
uv run src/generate_history.py

Targeting Specific Engines or Documents

# Single engine
uv run src/pdf_parser.py --engine opendataloader
uv run src/evaluator.py --engine opendataloader

# Single document
uv run src/pdf_parser.py --doc-id 01030000000001

# Both
uv run src/pdf_parser.py --engine opendataloader --doc-id 01030000000001

Project Structure

├─ charts/                 # Generated benchmark charts
├─ ground-truth/           # Reference annotations and structured ground truth
├─ history/                # Archived evaluation results by date
├─ pdfs/                   # Input PDF corpus (200 sample documents)
├─ prediction/             # Engine outputs grouped by engine/markdown
├─ src/                    # Conversion, evaluation, and utility scripts
└─ pyproject.toml          # Python dependencies (uv)

5. Contributing

Development Setup

# After following the installation steps above:
uv sync --dev

This installs development dependencies including pytest.

Running Tests

uv run pytest

Interpreting evaluation.json

Each engine produces an evaluation.json with:

• summary: Engine name/version, hardware info, document count, runtime, date.
• metrics.score: Mean scores (overall_mean, nid_mean, teds_mean, mhs_mean, etc.)
• metrics.*_count: Number of documents eligible for each metric.
• documents: Per-document scores and availability flags.

6. References

• Z. Chen, Y. Liu, L. Shi, X. Chen, Y. Zhao, and F. Ren. "MDEval: Evaluating and Enhancing Markdown Awareness in Large Language Models." arXiv preprint arXiv:2501.15000, 2025. https://arxiv.org/abs/2501.15000
• J. He, M. Rungta, D. Koleczek, A. Sekhon, F. X. Wang, and S. Hasan. "Does Prompt Formatting Have Any Impact on LLM Performance?." arXiv preprint arXiv:2411.10541, 2024. https://arxiv.org/abs/2411.10541
• D. Min, N. Hu, R. Jin, N. Lin, J. Chen, Y. Chen, Y. Li, G. Qi, Y. Li, N. Li, and Q. Wang. "Exploring the Impact of Table-to-Text Methods on Augmenting LLM-based Question Answering with Domain Hybrid Data." arXiv preprint arXiv:2402.12869, 2024. https://arxiv.org/abs/2402.12869
• M. Pawlik and N. Augsten. "RTED: A Robust Algorithm for the Tree Edit Distance." arXiv preprint arXiv:1201.0230, 2011. https://arxiv.org/abs/1201.0230
• Upstage AI. "Document Parsing Benchmark (DP-Bench)." Hugging Face, 2024. https://huggingface.co/datasets/upstage/dp-bench
• X. Zhong, J. Tang, and A. J. Yepes. "Image-based Table Recognition: Data, Model, and Evaluation." European Conference on Computer Vision Workshops, 2020. https://arxiv.org/abs/1911.10683
• X. Zhong, J. Tang, and A. J. Yepes. "PubLayNet: largest dataset ever for document layout analysis." International Conference on Document Analysis and Recognition, 2019. https://huggingface.co/datasets/jordanparker6/publaynet