Marlin Developer's Bench
The text editor for huge files
Only for Mac
$4.99
Mac
A three-gigabyte log opens the moment you ask for it. Search it, edit it, filter it down to the forty lines that matter, and save it back. Nothing leaves your Mac.
Marlin is a Mac text editor for the file you were dreading. The overnight server log that runs to three gigabytes, the CSV export your spreadsheet gave up on, the binary blob someone swears is only text. Marlin opens it straight away and lets you read it, search it, change it and save it, without ever pulling the whole thing into memory.
OPEN IT, HOWEVER LARGE
Files over 100 MB open in a streaming view. Marlin indexes the lines in the background and lets you move while it works, so Go to Line, search and the jump to the end are there from the first second. Edit a line in place, delete a run of lines, undo, then save. The save streams to disk and swaps the file in at the last moment, so a crash halfway through leaves your original exactly as it was, line endings and all.
A PIPELINE YOU CAN SEE
This is the part we are proudest of. Point Marlin at a log or a CSV and build a chain of steps across the top of the window: Match, Extract, Bucket, Sort and Unique. Every step shows how many rows it lets through, so you watch eighteen million lines narrow to twelve million and then to 744. Open any step later, change it, and everything after it follows. Your source file is never touched. When the result is right, export it, or keep the chain as a recipe for tomorrow's log.
AN EDITOR FOR EVERY DAY
The big files are why people find Marlin. The everyday editing is why they stay. Syntax coloring covers more than 30 languages, and you can add grammars of your own. There are tabs, split panes, a minimap, a folder tree, Open Quickly, and a command palette on Command-K that holds every command in the app. Search a whole folder with regular expressions and replace across every file in one step you can undo. Markdown, HTML, SVG, CSV and JSON get a live preview beside the text, and nine color themes cover light and dark.
HEX, WHEN TEXT IS NOT TEXT
Open any file as bytes. Click a byte and the inspector reads it at every integer and floating-point width, little-endian or big-endian, while Marlin names common file formats from their first few bytes. Jump to any offset by typing it.
COMPARE WITH WHAT IS ON DISK
See what you have changed since the last save, side by side, or put two open files against each other. If another app rewrites a file you have open, Marlin notices and asks before anything is overwritten.
A QUIET ASSISTANT
The assistant stays off until you switch it on. On a Mac with Apple Intelligence it uses Apple's on-device model, and on any other Mac it uses a built-in rule engine. Ask it to explain a selection, suggest a fix, diagnose a sudden spike of errors, name the columns in a CSV, or write the regular expression for a pipeline step. Whatever it reads stays on your Mac.
FROM THE TERMINAL
An optional marlin command opens a file at a given line, turns piped output into a new document, and can wait until you close the tab, which makes Marlin a comfortable editor for git commit messages.
PRIVATE BY DESIGN
Marlin makes no network connections. There is no account, no analytics and no tracking, and it reads only the files and folders you choose.
Requires macOS 14 or later. The Apple Intelligence mode of the assistant needs macOS 26 on a Mac that supports it. Runs natively on Apple silicon and Intel.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Follow: Go > Follow File (Option-Command-T) keeps a large log open as it grows. Marlin reads only the new bytes, keeps the last line in view, and shows "N new lines" when you scroll up. A rotated or truncated log is indexed again. A pipeline on the followed file adds the new rows as they arrive.
Timeline: a strip above a large log shows lines, warnings and errors over time, or over line numbers when the log has no timestamps. Click a bar to go to that moment. Drag across bars to select a range, then add it to the pipeline as a Time Range step that reads only that slice of the file, or ask the assistant about it. Go > Show Timeline (Option-Command-G) shows and hides it.
Columns: CSV, TSV and JSON Lines files open as a table with Go > Show as Columns (Option-Command-K). Click a column header to sort, filter, find unique values or count by value. Each action builds a pipeline step that runs on the whole file. Right-click a header to hide a column or to change the header row.
The developer, Zeeshan Khan, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Zeeshan Khan
- Size
- 9.3 MB
- Category
- Developer Tools
- Compatibility
Requires macOS 14.0 or later.
- Mac
Requires macOS 14.0 or later.
- Mac
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- Copyright © 2026 SixTwelve Studio. All rights reserved.
