Twain
How Twain compares
Twain reads, reviews and edits Markdown and MDX from Finder, without running the project. Here is how it stands next to the apps people weigh it against, with every fact dated and sourced. We also use these pages as our own gap list: when a rival ships something Twain should have, it goes on our roadmap, and the page changes when the gap closes.
Head to head
One page per rival, with the detail: what each app has that the other doesn't, and who should pick which.
Both are native Mac Markdown apps, but they do different jobs. Bear is a notes system with its own database. Twain reads, reviews and edits the Markdown and MDX files already on your disk.
Read the comparisonTypora is a syntax-free Markdown editor. Twain reads, reviews and edits Markdown and MDX files, with the Finder integration, MDX support and agent tooling Typora has never added.
Read the comparisonPeekdown previews Markdown and MDX in Finder for $3.99. Twain is a review workbench with a free viewer and free Quick Look at its core. The difference is what happens to the components, and what happens after you read.
Read the comparisonLettera, from the team behind Bear, edits Markdown files on disk in a native editor. It is the closest new app to Twain in intent, and the differences are specific.
Read the comparisonObsidian is a free, local-first knowledge base with 5,800+ community plugins. Twain opens a single Markdown or MDX file from Finder, with no vault and nothing to set up.
Read the comparisonMarked is the app closest to what Twain does: a preview window for the Markdown files you edit somewhere else. It is older, has broader export and processor options, and is priced very differently.
Read the comparisonThe whole field, in three groups
A Finder viewer, a publishing workstation and a knowledge base are different tools, so they are judged separately. Every fact is dated and sourced, and the tables change when a gap closes.
Finder-first viewers
Apps whose job starts with pressing space in Finder. This is Twain's home group.
| Twain | Peekdownverified 16 Jul 2026 | Glanceverified 16 Jul 2026 | MacMD Viewerverified 16 Jul 2026 | Marked 3 + Marked QLverified 20 Jul 2026 | |
|---|---|---|---|---|---|
| Finder Quick Look | Yes (MD + MDX) | Yes (MD + MDX) | Yes (MD) | Yes (MD) | Via Marked QL: separate $9.99 app |
| Opens .mdx from Finder | Yes | Yes | Not advertised | Not advertised | Not advertised |
| Renders MDX components as UI | Yes: safe allowlist, labelled unknowns | Opens MDX; strips or displays JSX | No | No | No |
| Editing | Pro: block-based visual editor, tables edited in place; source for MDX | Yes: source with live preview | Read-only by design | Read-only | No; pairs with your editor |
| Maths and Mermaid | Yes | Not advertised | Yes | Mermaid, code and tables | Yes |
| Local relative images | In the app (not in Quick Look) | Not verified | Yes | Not verified | Not verified |
| Review / AI workflow | Diagnostics, anchored notes, rendered diff, AI report, live refresh | Annotations export as AI prompts; auto-reload | Positions for reading AI output; intentionally tiny | Live reload, URL scheme | Proofing, CriticMarkup, processors, mk CLI, AppleScript; no rendered diff |
| Minimum macOS | macOS 14+ | macOS 15+ | macOS 14+ | macOS 14+ | macOS 12.4+ (Marked QL 13+) |
| Price | Free / $19 Pro, one-time, all your Macs; 7-day Pro trial | $3.99 one-time | Free (beta) | $19.99 one-time | $69.99 permanent (intro) or $2.99/month; QL $9.99 |
Marked 3 + Marked QL: Marked 3 (3.1.12) shipped May 2026 and takes point releases most months; Marked 2 is maintenance-only and still sold at $14.99. Marked QL is a separate $9.99 Mac App Store app, released 9 July 2026, working with or without Marked 3, and still lists dark mode as coming soon.
Document editors and publishers
Writing and publishing workstations. Twain covers reading, review and block-based editing, and exports HTML, PDF and presentations; their pipelines add formats like DOCX and EPUB.
| Twain | Letteraverified 17 Jul 2026 | Markd.lyverified 16 Jul 2026 | Typoraverified 16 Jul 2026 | iA Writerverified 16 Jul 2026 | Ulyssesverified 16 Jul 2026 | Caretverified 16 Jul 2026 | |
|---|---|---|---|---|---|---|---|
| Primary job | Read, review and edit Markdown/MDX | Native Markdown editor for files on disk | Document editor and publishing workstation | In-place Markdown authoring | Minimal long-form writing | Managed long-form writing and publishing | Minimal productivity-focused Markdown editor |
| Platforms | macOS | macOS only | Claims macOS, Windows and Linux (its pages conflict) | macOS, Windows, Linux | macOS, Windows, iPhone, iPad (separate purchases) | macOS, iPhone, iPad | macOS, Windows, Linux |
| Minimum macOS | macOS 14+ | macOS 26 (Tahoe) only, by the vendor's stated choice | Not verified | Not verified | Not verified | Not verified | Not verified |
| Export and publishing | Self-contained HTML (images embedded), PDF/print, presentations (Pro) | PDF, PNG, JPG, ePub; copy as HTML, RTF, TXT or Markdown | HTML/PDF + Pandoc DOCX, EPUB, LaTeX, RTF, Reveal.js, Beamer | PDF/HTML/image; Pandoc-backed DOCX/RTF; custom commands | HTML, PDF, DOCX and publishing flows | Blogs, ebooks, PDF, DOCX | Not central |
| CLI / automation | CLI on npm (twain-md: check, render, export, inventory); read-only MCP server ships in the app | No CLI or MCP | CLI, Vim mode, snippets, macOS MCP | Custom themes and export commands | Not central | Not central | Not central |
| MDX | Yes: safe component rendering | No | Not advertised | No | No | No | No |
| Finder Quick Look | Yes | No | Not advertised | No | No | No | No |
| Price | Free / $19 Pro, one-time, all your Macs; 7-day Pro trial | Not announced | $19.99 one-time (current main page) | $14.99, up to three devices; 15-day trial | Mac $49.99; Windows $29.99; iPhone+iPad $49.99 | $5.99/month or $39.99/year | $29 licence |
Lettera: In public TestFlight beta since 18 June 2026 and currently full behind a waitlist, so it cannot be bought or downloaded today. Shiny Frog (the Bear team) has not announced a price or a pricing model. Mermaid and MathJax had shipped by 1 July 2026.
Markd.ly: Its own pages conflict on platforms and price; treat with care.
Knowledge systems
A different category: databases, sync and collaboration. Twain opens the plain files these systems manage, straight from Finder, with no import step and no vault.
| Twain | Obsidianverified 20 Jul 2026 | Bearverified 17 Jul 2026 | Joplinverified 16 Jul 2026 | Inkdropverified 16 Jul 2026 | Notionverified 16 Jul 2026 | |
|---|---|---|---|---|---|---|
| Primary job | File-first viewer/editor; a vault-friendly companion | Local-first personal knowledge base | Apple-native notes system | Open-source synced notes and tasks | Developer-focused synced Markdown notes | Collaborative cloud workspace and database |
| Content model | Your plain files, wherever they live | Plain Markdown files in vaults | Managed note database; Markdown export | Markdown notes in an app-managed store (open format) | Managed notebook with encrypted sync | Cloud block database; Markdown import/export |
| Plain Markdown files | Yes (+ MDX) | Yes, inside a vault | Export only; cannot open external files in place | Managed store | Managed store | Import/export only |
| Sync and collaboration | None: files stay yours to sync | Optional paid Sync and Publish | iCloud sync (subscription); web app in free beta | Several sync options; Joplin Cloud from €2.99/month | Encrypted sync included | Realtime collaboration built in |
| Finder Quick Look | Yes | No | No | No | No | No |
| Price | Free / $19 Pro, one-time, all your Macs; 7-day Pro trial | Free, no account; paid Sync/Publish | $2.99/month or $29.99/year | App free; optional Joplin Cloud | About $9.98/month or $99.8/year; 30-day trial | Free and paid workspace plans |
Obsidian: Public release 1.12.7; 1.13.x is Catalyst-only early access. The commercial licence became optional in February 2025, so business use is free. Opening individual Markdown files outside a vault is listed as planned on Obsidian's public roadmap, not shipped.
Bear: Bear 2.9 at verification. 2.5 added LaTeX maths (MathJax); 2.8 added BearCLI, an MCP server and a Claude Connector; a web app is in free beta at web.bear.app. It cannot open external .md files in place: import copies them into its database.
“Yes/No” reflect each vendor's current public material as of the verification date shown under its name. “Not advertised” or “Not verified” means the vendor's material did not establish the capability, not that it is impossible. Prices are public US prices and can change. Generated from comparison-data.json (research basis: docs/COMPETITOR_COMPARISON.md adversarial review, 16 July 2026; Bear, Typora and Lettera detailed reviews, 17 July 2026).
Try it yourself
The free viewer renders Markdown and MDX from Finder, with a 7-day Pro trial built in.
Not shipped yet. The signed, notarised build is in progress; the download and checkout open together when it's ready.