36 formats across Office, PDF, web, data, email, eBooks, and notebooks — with availability and image support.

py-chunks handles 36 file extensions through one API. Dispatch is by file extension, so the extension (or the filename you pass with bytes) must be correct.

Availability

Stable = long-confirmed in the published packages. New = present in the engine source / latest builds; it may not be in your installed version yet — upgrade to pick it up (pip install -U py-chunks, npm i js-chunks@latest, cargo update). All 36 formats are supported by the shared engine; the published package descriptions may document a subset.

By family

Family	Extensions	Availability
Word	`.docx` `.doc`	Stable
	`.docm` `.dotx` `.dotm`	New
PowerPoint	`.pptx` `.ppt`	Stable
	`.potx` `.potm` `.ppsx` `.ppsm`	New
Spreadsheets	`.xlsx` `.xls`	Stable
	`.xlsm` `.xlsb` `.xltx` `.xltm` `.ods`	New
PDF	`.pdf`	Stable
Web & Markup	`.html` `.htm` `.md`	Stable
	`.rtf`	New
OpenDocument	`.odt` `.odp`	New
Plain & Data	`.txt` `.csv`	Stable
	`.tsv` `.json` `.jsonl` `.ndjson`	New
Email	`.msg` `.eml` `.mbox`	New
eBooks & Notebooks	`.epub` `.ipynb`	New

See Format examples for real engine output on the extended formats (JSON, email, RTF, EPUB, notebooks, and OpenDocument).

Chunking modes per format

Document formats (DOCX, DOC, PDF, PPTX, PPT, MD, HTML, TXT, MSG, EML/MBOX, ODT/ODP, JSON, RTF, EPUB, IPYNB): 7 modes — default, structural, section, semantic, sliding_window, sentence, page_aware.
Spreadsheets (XLSX, XLS, XLSM, XLSB, ODS, XLTX, XLTM): 6 modes — row, table, sheet, sliding_window, page_aware, semantic.
CSV / TSV: row (default), sliding_window, page_aware.

Markdown conversion

get_markdown supports documents, spreadsheets, and delimited files — Word, PowerPoint, PDF, HTML, Excel, CSV/TSV, TXT, Markdown, and the OpenDocument / email / eBook / notebook families. It does not accept URLs.

What each format produces

The conversion is format-aware — it maps each format's native structure to the closest Markdown construct rather than dumping plain text.

Format	Markdown output
`.docx`	Full fidelity: headings (`#`–`######` from Word heading styles / outline levels), unordered (`- item`) and ordered (`1. item`) lists with per-level indentation, pipe tables, fenced code blocks, hyperlinks as `[text](url)`, page/section breaks as `---`, footnotes/endnotes as `[^id]: text` appended at the end.
`.doc`	H1 → `#`, H2–H3 → `##`, H4+ → `###`; lists → `- item`; each table paragraph → a pipe row with a `\| --- \|` separator; page breaks → `---`.
`.pptx`	Presentation title → `# Title`; PPTX sections → `# Section`; each slide → `## Slide N: Title`; bullets (`- item` / `1. item`) with indentation; pipe tables; speaker notes as `> Notes: …`; slides/sections split by `---`.
`.ppt`	Slide titles → `##`; body placeholders → `- item` bullets (multi-line) or prose; freeform text boxes included; slides split by `---`.
`.pdf`	Headings inferred from font size vs document average → `#` / `##` / `###`; bullet lists normalized to `- item`; tab/space-aligned tables → pipe tables; page boundaries → `---`.
`.html`, `.htm`	H1–H6 → `#`–`######`; ordered/unordered lists; fenced code blocks; pipe tables with an auto-detected header row; `\|` in cells escaped.
`.xlsx`, `.xls`	Each non-empty sheet → `## SheetName` + a pipe table; sheets split by `---`.
`.csv`, `.tsv`	A single pipe table; first row = header with a `\| --- \|` separator; delimiter auto-detected or set explicitly.
`.md`, `.txt`	Returned as-is (no transformation).

With list_images=True, image-bearing formats additionally emit ![](hash.ext) references at the natural anchor point (top of each PDF page, after each Excel sheet, at the anchoring DOCX/DOC paragraph, inside the owning slide) and return the raw bytes in MarkdownResult.images.

Image extraction

list_images=True extracts embedded images for: DOC, DOCX (family), PPT, PPTX (family), XLSX (family — incl. ODS/XLSB, not XLS), HTML/HTM, PDF, EPUB, IPYNB, EML/MBOX, ODT/ODP.

Formats without image support: CSV, TSV, TXT, MD, JSON, RTF, MSG, XLS.

Only web-renderable formats are extracted (.png, .jpg, .jpeg, .gif, .webp); vector/metafile payloads (.emf, .wmf, .pict, .dib, .tiff) are silently skipped. Images are keyed by a stable content hash, so a picture that appears several times is stored once but referenced at each occurrence. PDF images are page-scoped and always re-encoded to .png. Image extraction is batch-only — see Streaming.

Format-specific notes

A few behaviors are worth knowing before you rely on a format:

PDF default vs structural differ (they are not aliases): default uses a fast lightweight path, structural runs full font-size layout analysis. A scanned / image-only PDF (no text layer) raises for text modes but succeeds under list_images=True, returning one image per page — see Error Handling.
DOC / PPT (97–2003) are parsed by a pure-Rust binary reader (no LibreOffice, no external process). Only Word 97+ .doc is supported — pre-Word 97 files raise. .doc page_number is always null (not present in the binary format); DOC table cells are joined with |.
PPT reads slides from the presentation's slide list in order; speaker notes and master text are excluded, and slides are separated by ---.
XLS vs XLSX: .xls cannot expose named tables or print areas, so table mode falls back to bounding-box detection and page_aware to the full sheet; .xls also returns no images. All other behavior matches .xlsx. See the Metadata Reference.
Header detection (spreadsheets/CSV): the first all-string row of each sheet is auto-detected as the header and excluded from chunk content; unlabeled columns become Column 1, Column 2, ….

Supported Formats