oxfmt 0.72: native Markdown formatter, Prettier 3.9.9 parity test, sorted imports in code fences (5 Oct 2026)

No affiliate links. This is a frontend tooling note based on the oxfmt v0.72.0 release, PR #27256, the npm registry, and a scratch test on ShopperCove’s own Markdown drafts. Nothing in ShopperCove’s production build was changed for this article.

Why oxfmt 0.72 matters if you use Prettier

oxfmt is the Oxc project’s Prettier-compatible formatter, and it is also bundled in Vite+. Up to 0.71.0 it formatted Markdown by handing the file to a bundled Prettier (0.71.0 bumped that to Prettier 3.9.9). Version 0.72.0 shipped on 5 Oct 2026 (npm 11:03 UTC / 16:33 IST; GitHub release 11:04 UTC / 16:34 IST). It has one breaking change:

• parser:markdown files are now formatted by oxc_formatter_markdown, Oxc’s own Rust Markdown formatter, instead of Prettier (#27256, merged 05:17 UTC / 10:47 IST).

The PR says the output is "basically the same" as Prettier 3.9.9 and already includes some fixes Prettier has not released yet. Differences are recorded in DIVERGENCES.md.

Because code fences are now formatted by oxc_formatter instead of Prettier’s babel/typescript path, sortImports and sortTailwindcss now apply to JS/TS inside Markdown fences. Fence languages are detected with Shiki language names. Block ::: directives work in both VitePress (::: tip) and remark-directive (:::tip) style.

ShopperCove test: 221 Markdown drafts, 0.71.0 vs 0.72.0 vs Prettier 3.9.9

On 5 Oct 2026 we installed oxfmt@0.71.0, oxfmt@0.72.0 and prettier@3.9.9 in separate scratch folders on an 8-thread Linux box with Node 20.19.2. We then formatted copies of 221 ShopperCove body-clean-cms.md drafts (about 2 MB) using default options and an empty .oxfmtrc.json.

Run	Wall time reported by the tool	Output vs Prettier 3.9.9
oxfmt 0.71.0 (Prettier-backed Markdown)	1,981–2,135 ms (3 runs)	Byte-identical on all 221
oxfmt 0.72.0 (native Markdown)	16–17 ms (3 runs)	Byte-identical on all 221

Both versions rewrote 186 of the 221 drafts (mostly * → _ emphasis, list markers, and table padding). They produced exactly the same bytes as each other and as Prettier 3.9.9. On this corpus the switch was invisible except for speed, roughly 120× faster. Your numbers will differ. Treat this as one site’s smoke test, not a benchmark.

Two differences we did reproduce

On a small hand-written file:

1. Sorted imports inside fences. With "experimentalSortImports": {} in .oxfmtrc.json, 0.72.0 reordered a ```js fence (react before zod, then a blank line before the relative ./a import). 0.71.0 and Prettier left the order alone. Without that config, 0.72.0 did not reorder anything. If your docs or MDX snippets are meant to show a specific import order, review the first 0.72 diff.
2. Pipe rows in a list continuation. A list item followed by unindented | not | table | and |---|---| lines (a lazy continuation, not a real table) was printed by 0.72.0 as one line: | not | table | |---|---|. 0.71.0 and Prettier kept two lines. This is the documented wrapped-block-starts divergence. Oxc joins the lines on purpose so the delimiter row cannot turn into a table the next time the file is parsed. Real tables separated by a blank line formatted the same in all three tools.

Chinese/Japanese line breaks were also preserved under every proseWrap setting (#27331, aligned with the unreleased Prettier 3.10).

Other fixes in 0.72.0

From the release notes:

• CSS: embedded CSS is now parsed as block contents, plus layout fixes found by running against the mdn-content repo (CSS inside Markdown).
• Ignore files: a negated pattern such as !vendor/keep.ts no longer re-includes a file under an excluded vendor/ directory when formatting explicit paths, stdin, or in the LSP (#27237). This now matches Git and Prettier.
• LSP: .prettierignore is reloaded when the file changes. Stdin mode checks global ignores before nested config and renders diagnostics with source.
• JS formatter: quoteProps: "consistent" now handles patterns and computed keys; comments between a callee and its opener stay on the callee side; embedded template layout is decided from the AST.
• JSON: arrays and objects that contain only a block comment are flattened.
• Performance: an exponential will_break check on nested interned content was removed, and the Markdown IR buffer is pre-allocated.

The same-day oxlint 1.87.0 (rule suggestions and a11y fixes) is covered separately.

Upgrade checklist

1. Pin oxfmt@0.72.0 on a branch and run oxfmt --check across **/*.md and **/*.mdx. Expect few or no diffs if you were already on 0.71.0 / Prettier 3.9.9.
2. If you enable experimentalSortImports or Tailwind class sorting, expect new diffs inside Markdown code fences. Commit them separately from content changes.
3. Search the diff for lines like | … | |---| inside lists (the wrapped-block-starts case) and for leading *** thematic breaks (the leading-thematic-break divergence).
4. If you rely on !pattern re-includes under an ignored directory, note that explicit-path formatting now skips those files.
5. Teams formatting with Prettier directly can stay on Prettier 3.9.9 (latest on npm as of 5 Oct 2026). Nothing changes for you until you adopt oxfmt or Vite+.

Bottom line

oxfmt 0.72.0 drops Prettier from its Markdown path. On ShopperCove’s 221 drafts the output stayed byte-identical to Prettier 3.9.9, and formatting took ~16 ms instead of ~2 s. The visible changes are opt-in import/Tailwind sorting inside fences and a short, documented list of intentional divergences. Pin, run --check, and review the first diff.

Sources

• https://github.com/oxc-project/oxc/releases/tag/oxfmt_v0.72.0
• https://github.com/oxc-project/oxc/pull/27256
• https://github.com/oxc-project/oxc/blob/main/crates/oxc_formatter_markdown/DIVERGENCES.md
• https://github.com/oxc-project/oxc/releases/tag/oxfmt_v0.71.0
• https://github.com/oxc-project/oxc/pull/27237
• https://github.com/oxc-project/oxc/pull/27331
• https://registry.npmjs.org/oxfmt
• https://oxc.rs/docs/guide/usage/formatter.html
• https://github.com/prettier/prettier/releases/tag/3.9.9

Related

• https://www.shoppercove.com/blog/oxlint-1-87-react-suggestions-a11y-fixes-october-2026
• https://www.shoppercove.com/blog/vite-plus-1-0-unified-toolchain-october-2026
• https://www.shoppercove.com/blog/biome-2-5-15-type-inference-nursery-rules-october-2026
• https://www.shoppercove.com/blog/eslint-10-12-release-october-2026
• https://www.shoppercove.com/blog/typescript-eslint-8-71-no-unsafe-enum-assignment-october-2026
• https://www.shoppercove.com/blog/astro-starlight-0-42-popover-js-dist-october-2026
• https://www.shoppercove.com/blog/rspack-2-2-8-resolver-cache-memory-october-2026
• https://www.shoppercove.com/blog/bun-1-4-2-elysia-als-cmyk-jpeg-october-20