# Layout and pagination parity with Microsoft Word

> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-10 · **Change:** major (first version; line breaking, pagination and object placement checked against Word's behaviour from the layout source on origin/main) · **Target:** Microsoft Word (Microsoft 365) for Mac 16.113.4

A document only "opens correctly" if its pages break where Word breaks them: the same lines, the
same page count, footnotes and pictures on the same pages. This checklist covers line breaking,
pagination and object placement in `crates/layout`. Typing behaviour is in
[`typing-parity.md`](typing-parity.md); the reading and writing of the properties is in
[`file-format-parity.md`](file-format-parity.md).

**Dimension: ~55% (estimated), 90–145 h to full** (the sum of the rows below). The engine implements most of Word's layout
rules, but nothing has been compared page-for-page with Word on real documents, and the default
font can't match Word's metrics.

## Checklist

✅ matches Word as far as our tests show · 🟡 implemented, differs or untested against Word · ❌ missing

| Feature | State | Evidence / gap | Hours |
|---|---|---|---|
| Line breaking (UAX #14 with Word's exceptions: no break after `/`) | ✅ | `layout::tests::no_line_break_right_after_a_slash` | — |
| Justification, Word 2013+ space shrinking (compat mode 15) | ✅ | #109 | — |
| Kashida justification (Arabic) | ❌ | no kashida in `crates/layout` | 3–5 |
| Distributed / Thai distributed alignment | 🟡 | read; layout untested | 1–2 |
| Default font metrics (Aptos, Calibri, Cambria…) | 🟡 | Carlito/Caladea/Liberation are metric-compatible for Calibri/Cambria/Arial/Times/Courier; **Aptos (Word's default since 2024) has no metric-compatible open substitute**, so new Word documents wrap differently ([typing-parity.md](typing-parity.md) Known gaps). Needs an owner decision (commission or license a metric-matched font) | 6–10 + owner |
| Line spacing (single, 1.5, double, at least, exactly, multiple), spacing before/after, contextual spacing | 🟡 | Word puts multiple-spacing extra below the text and collapses spacing differently (#135, #108 open) | 3–5 |
| Widow/orphan control, keep with next, keep lines together, page break before | ✅ | `lib.rs` keep_next/keep_lines | — |
| Tabs (left, center, right, decimal, bar), leaders | 🟡 | Bar tabs untested | 1–2 |
| Hyphenation (automatic, 0.25" zone, soft hyphens, consecutive limit) | 🟡 | English patterns only; other languages hyphenate wrongly or not at all | in localization |
| Drop caps | ✅ | 2026-10-06 | — |
| Columns, column breaks, separators | 🟡 | **Columns don't balance** at a continuous section break or document end | 4–6 |
| Section breaks (next page, continuous, even, odd), different first page, odd/even headers | ✅ | Section breaks don't show in Draft view (#42) | 1–2 |
| Body top below a tall header, footer pushes body up | ✅ | #138 | — |
| Footnotes at the page bottom, endnotes at the end, note numbering | 🟡 | **A long note doesn't continue onto the next page**; no continuation separator/notice; per-section restart partial | 4–6 |
| Tables: row heights (at least/exact), rows split across pages, header rows repeat, Can't Split | ✅ | 2026-10-06, #138 | — |
| Tables: autofit to contents/window, fixed widths, Word 2013 edge | 🟡 | #137; #44: AutoFit Contents measures each column's narrowest and widest text and shares the width like Word, once (not live as you type); cell preferred widths and spans still differ | 3–5 |
| Floating tables (`w:tblpPr`) | 🟡 | #137; overlap rules untested | 2–3 |
| Nested tables | 🟡 | render; polish missing | 2–4 |
| Floating pictures/shapes placement (relative to page/margin/column/paragraph/line/character) | ✅ | #136 | — |
| Text wrap: square, top-and-bottom, behind, in front | ✅ | 2026-10-06 | — |
| Text wrap: tight, through (contour, wrap polygon) | ❌ | laid out as square | 6–10 |
| Text boxes, overflow, linked text boxes | 🟡 | #46; linked text boxes missing | 3–5 |
| Rotated objects and text | ❌ | no rotation in layout | 4–6 |
| Page borders (from page edge or text), page colour, watermark | ✅ | | — |
| Line numbers (restart per page/section, count by) | ✅ | | — |
| Vertical page alignment | ✅ | | — |
| Gutter, mirror margins, book fold, 2 pages per sheet | 🟡 | gutter and mirror margins; book fold missing | 2–3 |
| Document grid (`w:docGrid`, lines per page, characters per line) | ❌ | East Asian documents paginate differently without it | 4–6 |
| Vertical text (`tbRl`) in sections and text boxes; cell text direction | 🟡 | cell text direction landed (#245); page-level and text-box vertical text missing | 8–12 |
| Ruby / phonetic guide, enclose characters, combined characters | ❌ | | 4–6 |
| Bidirectional paragraphs, mixed-direction lines | 🟡 | #207; RTL sections and tables (`w:bidiVisual`) missing | 4–6 |
| Equations: display layout, numbering | 🟡 | #191; long display equations don't break across lines | 3–4 |
| Hidden text excluded from breaking and hyphenation | ✅ | #173 | — |
| Fields: PAGE, NUMPAGES, SECTIONPAGES, TOC page numbers | ✅ | #52 | — |
| Compatibility modes (Word 2003/2007/2010 layout for old files: `w:compat` options) | 🟡 | mode 15 behaviour; the ~60 legacy compat options are mostly ignored | 10–20 |
| Page-by-page comparison harness against Word | ❌ | Run Word locally on our own synthetic documents, export PDF, compare line breaks; Word output stays under `plan/` (never committed) | 8–12 |

## Performance

| Measure | WordCraft | Word | Kind |
|---|---|---|---|
| Cold layout, 188-page document | 61 ms | not measured | measured 2026-10-06 (not re-run this pass) |
| Relayout after an edit | 1.4 ms | not measured | measured 2026-10-06 |
| Font picker with many installed fonts | fixed freezes (#233) | instant | issue #31, #59 |
| Large real-world documents (500+ pages, many pictures) | not measured | | gap |

## Revision history

| Date | Change | Summary |
|---|---|---|
| 2026-10-10 | trivial | AutoFit Contents measures the text (#44) |
| 2026-10-10 | major | First version: layout and pagination checklist with evidence from `crates/layout`, PRs and issues |