dongler-core 0.3.16

Rust-native PDF and document extraction core for Markdown, LaTeX, and JSON output.
Documentation

Dongler is built around a path-first workflow: load a file, inspect the document object when you need to, then render the output format your pipeline wants. One Rust core powers the CLI, Python, TypeScript, and Rust APIs, so the extraction model is identical everywhere.

Install

cargo install dongler                  # CLI + Rust
pip install dongler                    # Python
npm install @cristianexer/dongler      # Node / TypeScript

For the Rust library, depend on dongler-core. The public dongler crate is the CLI package.

To run extraction in the browser or another WebAssembly host, build the dongler-wasm crate (make build-wasm). It exposes the same engine over an in-memory byte API, so files can be parsed client-side with no server. See crates/dongler-wasm/README.md.

Parse a PDF

Python

import dongler

doc = dongler.load("report.pdf")
markdown = doc.to_markdown()
latex = doc.to_latex()
data = doc.to_dict()

TypeScript

import { load } from "@cristianexer/dongler";

const doc = load("report.pdf");
const markdown = doc.toMarkdown();
const latex = doc.toLatex();
const data = doc.toObject();

Rust

use dongler_core::load_path;

let doc = load_path("report.pdf")?;
println!("{}", doc.to_markdown()?);

What you get

๐Ÿ“„ Markdown ยท LaTeX ยท JSON Three renderers from one document object โ€” headings, tables, lists, figures, and emphasis.

โšก Native speed, local runtime A custom Rust PDF parser with rayon page-parallelism. No hosted service, API key, LLM, or OCR for born-digital PDFs.

๐Ÿงฑ Structured document model Page, block, table, image, span, warning, and metadata fields โ€” with source anchors back to PDF objects.

๐Ÿงฉ One API across stacks The same extraction model in Python, Node.js, Rust, and the CLI.

๐Ÿ“ฆ Pipeline-friendly batches Batch APIs return one result per file โ€” a single bad document never stops the job.

๐Ÿ”Œ Beyond PDF Native extraction for DOCX/XLSX/PPTX, ODT/ODS/ODP, HTML/XML, EML, JSON/JSONL, CSV/TSV, images, and archives.

Why Dongler

Use Dongler when the job starts with a document path and the next step needs useful text quickly:

  • Convert PDFs to Markdown for indexing, review, or RAG ingestion.
  • Keep page/block/table/image metadata available through JSON.
  • Run locally in scripts, services, queues, notebooks, and shell workflows.
  • Use the same extraction model across Python, Node.js, Rust, and the CLI.

Supported inputs

Dongler focuses on digitally born PDFs and also supports native extraction for DOCX, XLSX, PPTX, ODT/ODS/ODP, HTML/XML, EML, JSON/JSONL, CSV/TSV, image metadata including TIFF, and plain text/Markdown/TeX. It also reads gzip-compressed text/JSON/XML/CSV corpus files, bare gzip source files, and zip/tar/tar.gz source packages. Legacy binary Office and Outlook containers are detected and return explicit planned-format errors until their engines land.

Batch processing

One result per file โ€” a bad or unsupported document does not stop the batch.

import dongler

for result in dongler.load_many(["notes.txt", "invoice.pdf"]):
    if result["ok"]:
        print(result["document"].to_markdown())
    else:
        print(f"{result['path']}: {result['error']}")

CLI

dongler --version
dongler inspect invoice.pdf
dongler extract report.docx --format markdown
dongler extract book.xlsx   --format json
dongler extract notes.txt   --format latex

PDF extraction through the CLI uses the same Rust-native engine as the Rust, Python, and TypeScript packages.

Documentation

Benchmarks

Dongler sustains ~90 born-digital pages/second on a single host with no GPU, and on olmOCR-Bench (1,403 real PDFs, 7,019 unit checks) its table-structure pass rate improved +9.7% relative over the previous release on the identical harness. Full results, methodology, and before/after examples are on the benchmarks page.

Generated by scripts/run-benchmarks.py on 2026-05-28 19:56:50 BST. Local cache: 1894.9 MB. All discovered files per dataset. olmOCR-Bench re-measured 2026-06-11 after the table-extraction work; the full table regenerates on the next release run.

Coverage is parse / bbox / anchors. Ground-truth accuracy is token-F1, olmOCR unit-check pass rate, or full-image IoU; n/a means no local target signal. Detailed task names, discovery counts, native scores, and notes are recorded in eval/out/benchmarks/latest.json.

Dataset Status Local data Docs eval Coverage Pages/sec GT accuracy
DocLayNet missing 0.0 MB 0 n/a / n/a / n/a n/a n/a
PubLayNet missing 0.0 MB 0 n/a / n/a / n/a n/a n/a
DocBank ok 735.6 MB 200 100.0% / 100.0% / 100.0% 81.94 89.5%
PubTabNet missing 0.0 MB 0 n/a / n/a / n/a n/a n/a
PubTables-1M missing 0.0 MB 0 n/a / n/a / n/a n/a n/a
TableBank ok 1.6 MB 10 100.0% / 100.0% / 100.0% 193.45 100.0%
FUNSD ok 42.6 MB 200 100.0% / 48.9% / 100.0% 96.09 100.0%
SROIE ok 627.3 MB 1264 100.0% / 92.7% / 100.0% 231.85 100.0%
RVL-CDIP missing 0.0 MB 0 n/a / n/a / n/a n/a n/a
READoc ok 39.9 MB 959 100.0% / n/a / n/a 96.86 100.0%
OmniDocBench ok 40.3 MB 1 100.0% / 100.0% / 100.0% 1030.96 88.5%
olmOCR-Bench ok 340.5 MB 1403 100.0% / 100.0% / 100.0% 21.15 22.7%
ckorzen benchmark ok 67.1 MB 192 100.0% / 15.4% / 100.0% 100.37 88.4%
S2ORC missing 0.0 MB 0 n/a / n/a / n/a n/a n/a
PMC OA missing 0.0 MB 0 n/a / n/a / n/a n/a n/a
arXiv source/PDF missing 0.0 MB 0 n/a / n/a / n/a n/a n/a

Extraction-quality improvements

A controlled A/B of the current parser against the previous release baseline โ€” run on the full olmOCR-Bench corpus (1403 real PDFs, 7019 unit checks, identical harness and release build) โ€” isolates the gains from the recent text-spacing and table-structure work:

Signal Before After
olmOCR table-structure checks passed 59.7% 65.5% (+9.7% relative)
olmOCR reading-order checks passed 30.7% 32.0%
Overall olmOCR checks passed 1562 / 7019 1595 / 7019
Throughput (born-digital) ~90 pages/sec ~90 pages/sec

Born-digital word segmentation is fixed end to end (UNITEDSTATES โ†’ UNITED STATES, Netincome โ†’ Net income, fi scal โ†’ fiscal), and multi-section financial statements now extract as a single aligned table โ€” in Markdown, LaTeX, and JSON โ€” instead of a label column followed by a detached block of numbers. See the benchmarks page for the full breakdown.

License

Dongler is MIT licensed. Copyright (c) 2026 Daniel Fat. See LICENSE and NOTICE for the full notice text.