Bike Outliner vs Understory

Bike Outliner

• Mac users who want a fast, minimal outliner
• Writers who draft in outline form with focus and typewriter modes
• People who want outlines kept as open HTML, OPML or text files

Understory

• Students and researchers turning reading notes into a paper
• Writers who outline before drafting an essay, script or book
• Mac users who want notes kept as plain Markdown files

Bike Outliner

• It is a Mac app only; the site lists no iPhone, iPad, Windows or web version.
• Rich text, row types, focus and typewriter modes, Shortcuts actions and AppleScript are locked in free mode.
• The one-time license covers one year of updates; later updates need a renewal, offered at half price.
• Copies from the Mac App Store or Setapp are unlocked by subscription only, not by the one-time license.

Understory

• It is a Mac app only, requiring macOS 14.8 or later; the FAQ says there is no iPhone or iPad version yet.
• The free version stops at 100 notes in the Personal Notebook and 20 in each Project Notebook.
• Sync between Macs covers only the Personal Notebook and needs an iCloud account; Project Notebooks are local folders.
• The App Store release notes for version 1.1 (October 2026) describe the Publish feature as experimental.

Bike Outliner

Outlining built for speed

Designed to handle very large outlines and to stay quick at basics such as opening files, scrolling and resizing windows.

Rich text and row types

Format text as bold, italic or links, and mark rows as headings, ordered lists, task lists and more. Both are unlocked by a license.

Distraction-free writing modes

Full screen, typewriter and focus modes, with live word counts and other text statistics in the status bar. Focus and typewriter modes need a license.

Open file formats

The native .bike format is HTML that can be viewed in a web browser, and Bike also reads and writes OPML and plain text files directly.

Links and navigation

Deep links into an outline keep working when the file is renamed or moved, and a navigation bar offers back and forward controls and a breadcrumb trail.

Scripts and Shortcuts

AppleScript and Shortcuts actions let other applications control Bike and fit it into existing workflows. Both need a license.

Understory

Notes and subnotes

A note is plain text and needs no title or filename. Any note can hold subnotes, each a full note with its own text, links and attachments, so a note grows into a tree.

One note in several outlines

The same note can appear in more than one tree without being copied. An edit in one place shows up in the others, and shared notes are shown in italics.

Two-way links

Wiki-style links connect notes in the text, and the linked note shows a backlink automatically. Anchors can point to a specific place inside another note.

Publishing

Selected notes or a whole outline can be published in their arranged order as a PDF with bookmarks and page numbers, Rich Text, Markdown or a website, or printed.

Markdown folders or iCloud

A Project Notebook is a folder on the Mac holding one Markdown file per note. A Personal Notebook lives in the user's own iCloud account and syncs between Macs.

Version history

Every version of a note is kept, so an earlier draft can be read again and brought back. Deleted notes go to a trash.

Bike Outliner

• Free mode$0

  Core outlining with no time limit: read, write and edit outlines saved as .bike, OPML or plain text files.

• Bike License – Monthly$2.99

  per month, Mac App Store subscription

  Unlocks all features in the Mac App Store copy for as long as the subscription is active.

• Bike License – Yearly$19.99

  per year, Mac App Store subscription

  The same Mac App Store subscription billed once a year.

• One-Time Purchase License$29.99

  one-time, includes one year of updates

  Sold on the Hog Bay Software site. Unlocks all features; updates released within the year keep working unlocked afterwards.

Understory

• Free$0

  Up to 100 notes in the Personal Notebook and 20 in each Project Notebook, with every feature included, from publishing to iCloud sync.

• One-Time Payment$24.99

  one-time purchase (US Mac App Store)

  Removes the note caps and opens shared notebooks of any size for editing. The vendor notes that the App Store sets a different price in each region.

Bike Outliner

• Other savings

  License renewal at 50% off

  After the first year, a one-time license can be renewed for another year of updates at half price; the renewal is listed at $14.99 in the vendor's checkout.

• Annual discount

  Yearly subscription costs about 44% less

  On the Mac App Store the yearly Bike License is $19.99 against $2.99 a month, which works out to about 44% less over twelve months.

Understory

No public discounts listed.