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MrEditor for Mac

Ultra-fast viewer and editor for 10 GB+ text files with instant open, full-text search, and atomic saves.

By MR-TABATA. Free and open source, MIT licence.

Get it with OpenDMG View source on GitHub

MrEditor at a glance

Version
1.21.0
Released
8 October 2026
Download size
2.4 MB
Works on
Apple silicon and Intel
Licence
MIT
Category
Writing and Editors
Developer
MR-TABATA
GitHub stars
35

About MrEditor

86,420,337 lines — a 10 GB log — open in 80 ms, and 0 bytes of it live in memory. A Mac-native viewer and editor for the files that break everything else: edit in place, save with atomic writes, diff and merge side by side.

Screenshots

MrEditor screenshot 1MrEditor screenshot 2

How to install MrEditor on a Mac

  1. Get OpenDMG. It is a free app store for open source Mac apps. Download OpenDMG.
  2. Search for MrEditor and press Get. OpenDMG downloads version 1.21.0 from MR-TABATA's own GitHub release.
  3. Open it. The download is checked against its SHA-256 fingerprint and its signature is checked on your Mac before it lands in Applications.

Updates to MrEditor show up in OpenDMG and install with one button. No account is needed.

Prefer to do it by hand? The developer's file is on GitHub: MrEditor-1.21.0.dmg (2.4 MB).

What is new in MrEditor 1.21.0

- **Click a line number to set or clear a bookmark**, in the large-file viewer and in the editor. Bookmarks have been here since 1.13.0, but only through the menu or ⌘B, so few people found them.
- **A bookmark button beside the funnel in the search bar shows only the marked lines.** Search, mark, search again, mark — then look at just the marks. Press it again to bring the whole file back. It is exclusive with the funnel, and editing the search ends it. In this view a click on the gutter clears a mark but keeps the line (so you can put it back); a double click removes the mark and the line.
- Fixed: bookmarks set in a small file while a filter was on were stored by the row on screen, not by the line in the file, so they moved when the filter was lifted. They are kept by the line's position in the original file now.

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