docxide-pdf
Library and CLI for converting DOCX files to PDF, matching Microsoft Word's output as closely as possible.
🫶 Accessible: Output PDFs should be just as accessible as Word's export, or better: tagged structure, reading order, language and metadata that pass the same PDF/UA checks.
🎯 Accurate: Given a .docx file, produce a .pdf that is visually identical to what Word would export.
⚡️ Fast: Typical conversions complete in under 100ms.
🤏 Small files: Output PDFs should be the same size or smaller than Word's export.
Reference PDFs are generated using Microsoft Word for Mac (16.106.1 and later). Most (173 of 234) use the "Best for electronic distribution and accessibility (uses Microsoft online service)" export option; the other 61 were made with "Best for printing", macOS's untagged print path.
⚠️ Work in progress.
This crate might work for your production case, do give it a try! The API, output quality, and supported features are all actively changing.
Comparison with other converters
Every fixture in the test corpus rendered side by side by Word (the reference) and
- docxide-pdf (duh)
- LibreOffice
- MiniPdf's Rust crate
- rdocx
- office2pdf
- jubarte-redlines.
Each engine is scored against the Word reference with the same metrics the test suite uses: three for how the pages look, and one for how accessible the PDF is.
| Metric | What it measures |
|---|---|
| J (Jaccard) | Overlap of ink pixels at 150 DPI. Strict: a one-line vertical shift sends it toward zero. |
| SSIM | Structural similarity on 8×8 windows with ±8 px vertical tolerance, so small drift is forgiven. |
| TB (text boundary) | Share of lines whose first and last word match the reference. Measures line breaking and pagination, independent of fonts. |
| a11y | PDF/UA-1 rules failed (veraPDF), how many of those Word passes, and how closely the tag structure and screen-reader text order match Word's. |
Got a weird DOCX?
If you have a .docx file that produces ugly, broken, or just plain wrong output, send it to me! Real-world documents with surprising formatting are the best way to improve. Open an issue or PR with the file included and I will try to make it work.
AI usage disclaimer 🤖
While the idea, architecture, testing strategy and validation of output are all human, the vast majority of the code as of now is written by various Claude models with access to the PDF specification (ISO-32000) and the Office Open XML File Formats specification (ECMA-376). This project was done as an exercise to get experience with the usage of coding agents.
Supported features
- Text: font embedding (TTF/OTF/TTC), bold, italic (sheared when the face has no italic), single and double underline, strikethrough, double strikethrough, font size, text color, superscript/subscript, small caps, all caps, character spacing, text expansion/compression (
w:w), hidden text (w:vanish), kerning (legacy kern table + GPOS PairAdjustment), run borders with color/width/spacing, run shading (w:shd) and highlighting, legacy text-effect toggles (w:outline,w:shadow,w:emboss,w:imprint), Word 2010 text effects (w14:glow,w14:shadow,w14:textOutline, gradientw14:textFill), symbols (w:sym), positional tabs (w:ptab), non-breaking hyphens, UAX #14 line breaking - Paragraphs: left/center/right/justify/distributed alignment (
distribute), space before/after, line spacing (auto, exact, at-least), first-line and hanging indentation, left/right indentation, contextual spacing, keep-next, keep-lines, paragraph borders (top/bottom/left/right/between) with color, paragraph shading, text frames (w:framePr) - Styles: paragraph and run style inheritance (
basedOnchains), document defaults fromdocDefaults(all run properties: bold, italic, caps, smallCaps, vanish, strikethrough, dstrike, underline, color, char_spacing), theme fonts and colors - Lists: bullet and numbered lists with multi-level nesting, custom number formats (incl. CJK:
decimalEnclosedCircle,decimalFullWidth,aiueoFullWidth), list style inheritance,w:lvlRestart,w:lvlOverride/w:startOverride,w:isLgl,w:suff,w:pStylelevel association - Tables: column widths with auto-fit, merged cells (horizontal
gridSpanand verticalvMerge), row heights (exact and minimum), per-cell borders with color/width, inlinew:tblBorders, cell shading, pattern/hatch shading, vertical alignment, cell text direction (rotated cells, vertical CJK), cell margins, floating/positioned tables (tblpPr), nested tables, conditional formatting (tblLook/tblStylePr— banded rows/columns, first/last row and column), repeated header rows (tblHeader),cantSplit, Word-compatible row splitting across pages - CJK text: CIDFont/Identity-H/ToUnicode encoding, Word-compatible substitution of missing CJK fonts by fontTable charset and family (Batang/Malgun Gothic/MS Mincho/SimSun/…, then Apple and Noto faces), per-character font fallback at render time, script-based run splitting via
w:rFonts @eastAsia, Word's East Asian line height,compressPunctuation,autoSpaceDE/autoSpaceDN - Images: inline JPEG/PNG/BMP/GIF/TIFF embedding with sizing and alpha transparency, grayscale and CMYK JPEG support, cropping (
a:srcRect), EMF/WMF vector translation to PDF form XObjects, anchored/floating images with wrap modes (square, tight, through, topAndBottom), floating image positioning relative to page/margin/column, rotation, clipping to shape geometry, behind-document z-ordering, OLE objects (w:object) drawn from their preview picture - Picture effects: outer shadow (
a:outerShdw), inner shadow, glow, soft edges, reflection — rasterized blur masks via SMask - Text boxes: DrawingML textboxes (
wps:txbx) and VML fallback (v:textbox), shape fills (solid color with theme color support including lumMod/lumOff, linear gradients with multiple color stops), textbox body margins - WordArt: modern DrawingML WordArt with all 40
prstTxWarppresets — two-path envelope warping (wave, slant, inflate, etc.) and single-path text-on-a-path (arch, circle), text outlines, shadows, glow effects, bold/italic font variant selection, VML WordArt fallback - Shapes & geometry: all 187 OOXML preset shapes via formula-based geometry engine (guide formulas, adjustment values), custom geometry paths (
a:custGeomwith moveTo, lineTo, cubicBezTo, arcTo), shape fills and strokes, drawing canvases (wpc:wpc) and shape groups (wpg:wgp/grpSp) flattened with nested transforms, connectors - Charts: bar (clustered/stacked/percent-stacked, vertical/horizontal), line, pie, area, doughnut, radar, scatter, bubble — with axis labels, tick marks, gridlines, legends, series markers, bubble fill opacity
- Math: Office Math (OMML) equations, inline and display (
m:oMathPara) with justification - Page layout: page size, margins, gutter margins, document grid (
linePitch), page borders (w:pgBorders), vertical page alignment (w:vAlign), line numbering (w:lnNumType), explicit page breaks,pageBreakBefore, automatic page breaking with widow/orphan control - Sections: multiple sections with
nextPage/continuous/oddPage/evenPagebreaks, per-section page size and margins, blank page insertion for odd/even page alignment - Multi-column layout: 2+ columns with custom widths and spacing, column breaks, column separators
- Headers/footers: default, first-page, and even/odd variants, per-section headers/footers, STYLEREF field resolution (spec-compliant backward search), page number and page count fields, images in headers/footers, correct z-ordering (behind body content)
- Footnotes & endnotes: footnote references and page-bottom rendering with separator line, endnotes flowed at document end, per-section mark numbering formats, shading on reference marks
- Comments:
word/comments.xmlrendered in Word's right-hand review pane with callouts and body scaling - Fields: PAGE, NUMPAGES, PAGEREF, STYLEREF (with spec-compliant search order) in complex
w:fldCharfields, cached results for every other field (and forw:fldSimple) - Hyperlinks: clickable external links (URI link annotations) and internal links (bookmarks, footnote marks)
- Tab stops: left, center, right, decimal; dot, hyphen and underscore leaders
- Track changes: final mode (insertions included, deletions removed — matches Word's PDF export)
- SmartArt: rendering via pre-flattened drawing shapes (
dsp:drawing) with full geometry engine support — all 187 preset shapes, custom geometry, fills (solid, gradient, image), strokes, and text - Document settings:
word/settings.xmlparsing — even/odd headers, default tab stop interval,gutterAtTop,themeFontLang,characterSpacingControl,compatibilityMode,linkStyles,doNotExpandShiftReturn - Compatibility:
mc:AlternateContentfallback, structured document tag (w:sdt) content extraction,w:customXmltransparent wrappers,altChunkHTML content parsing, smart tag handling, VML fallbacks for shapes, textboxes, WordArt andw:objectembeds - Fonts: cross-platform font search (macOS/Linux/Windows), embedded DOCX font extraction and deobfuscation, font subsetting (CIDFont/Type0), disk-cached font index, Word's missing-font substitution (
fontTable.xmlaltName, then Cambria or Calibri by family class) - Accessibility: tagged PDF structure tree (headings, lists, tables, figures with alt text, links, notes, TOC), document and per-run language, XMP metadata, bookmarks from headings, PDF/UA-1 claimed when the document allows it
- Output optimization: font subsetting, content stream compression, compressed object streams
Not yet supported
- Text: text shaping/ligatures (fi, fl), complex script shaping (Arabic, Devanagari, etc.), automatic hyphenation (parked — Word's online converter doesn't hyphenate either), underline styles other than single/double, underline color, raised/lowered text (
w:position), emphasis marks,w:fitText, ruby, drop caps, vertical text outside table cells - Images: wrapping around floats anchored more than one paragraph below the text, more than one wrapping float at a time, tight vs through wrapping distinction
- Layout: mirror margins (
w:mirrorMargins, not parsed), right-to-left (bidi) text, kashida justification (mediumKashida/highKashida/lowKashidarender as plain justify — glyph elongation needs Arabic shaping),w:textAlignment, page background color - Tab stops: bar tabs, middle-dot and heavy leaders
- Track changes: moved text (
w:moveTo) is dropped - Charts: 3D charts (3D pie is drawn flat), stock charts, combo charts (first chart type only), data labels, chart titles, secondary axes
- Shape effects: shadow/glow/soft edges on shapes and text boxes (pictures only), dashed outlines (
a:prstDash), 3D bevel/rotation (a:scene3d,a:sp3d), preset shadows (a:prstShdw), radial/path gradient fills (drawn as linear) - SmartArt: no layout engine for documents missing the
dsp:drawingfallback (see roadmap) - Features: table of contents generation (cached TOC results are drawn), embedded OLE object data (only the preview picture is drawn)
- Fonts: bundled fallback fonts (without the document's fonts installed, Arial/Liberation Sans/DejaVu Sans or Helvetica stand in)
Examples
Every test case rendered as a Word reference and with docxide-pdf on the comparison page.
Installation
# Install the CLI
Usage
CLI
# Convert a DOCX file to PDF
# Specify output path (defaults to input.pdf)
The CLI never overwrites: if the output exists it writes output(2).pdf, output(3).pdf and so on. RUST_LOG=info prints timings.
Library
This avoids pulling in the CLI dependency (clap).
use convert_docx_to_pdf;
use Path;
convert_docx_to_pdf?;
Works well with docxide-template
docxide-template is a sibling crate for type-safe MS Word templates. It scans a folder of .docx files at compile time and generates a Rust struct per template, with {Placeholder} patterns turned into snake_case fields. Pair it with docxide-pdf to go from template → filled DOCX → PDF in a single, fully in-memory pipeline:
use convert_docx_bytes_to_pdf;
use generate_templates;
use Path;
generate_templates!;
100% Rust, end to end — no temporary files, and no Word or LibreOffice install required on the host. Fill the template in memory, hand the bytes to convert_docx_bytes_to_pdf, and write the PDF. Combined with docxide-template's embed feature, you get a single self-contained binary that turns structured data into a polished PDF.
Configuration
Environment Variables
| Variable | Description |
|---|---|
DOCXSIDE_FONTS |
Additional font directories to search, colon-separated (; on Windows). Lowest priority: used for families the system font directories don't provide. |
DOCXSIDE_NO_FONT_CACHE |
Set to any value to disable the font index disk cache. Forces a full font scan on every conversion. Useful for debugging font resolution issues. |
Font scanning results are cached to disk (per-directory, invalidated by mtime). The cache is stored at:
- macOS:
~/Library/Caches/docxide-pdf/font-index.tsv - Linux:
$XDG_CACHE_HOME/docxide-pdf/font-index.tsv(default~/.cache/) - Windows:
%LOCALAPPDATA%\docxide-pdf\cache\font-index.tsv
Testing
Tests require mutool on PATH for PDF-to-PNG rendering:
# Run all tests with a compact report of what changed
# Run only the visual comparison (Jaccard and SSIM)
.cargo/config.toml points DOCXSIDE_FONTS at a fonts/ directory that isn't in the repository (the fixtures' fonts can't be redistributed). Without those fonts many fixtures fall back to substitutes and score lower. The accessibility test also needs veraPDF and Poppler (brew install verapdf poppler) and skips without them.
SCORING.md explains every score: the visual metrics, the accessibility metrics and what fails the suite.
Debugging Tools
Build the tools once:
&&
Then run from the project root:
# Inspect XML inside a DOCX
# Print font information
# Compare two rendered pages
# Full fixture diff
# Browse reference vs generated pages per fixture, with notes
# Fixture features and scores, e.g. only the failing ones
Contributing
Pull requests are welcome!
License
Apache-2.0