---
title: ".lock file — what it is and how to open it"
description: "A .lock file is a Lock File. Either a dependency version record or a marker saying a file is in use. How to open one on Windows, macOS and Linux, and what to convert it to."
url: https://atoneplace.net/file/lock/
site: "At One Place"
---

# .lock files

**.lock file: Lock File**

Either a dependency version record or a marker saying a file is in use.

## What opens a .lock file

- **Windows:** Visual Studio Code, Notepad (built in)
- **macOS:** Visual Studio Code, TextEdit (built in)
- **Linux:** Visual Studio Code, Text Editor (built in)

## What a .lock file is

Two unrelated things use this extension. Package managers write lock files — yarn.lock, Cargo.lock, poetry.lock — recording the exact dependency versions installed, and those are plain text that belongs in version control. Separately, applications and databases create a .lock file to signal that a resource is open; a stale one left after a crash is what causes "the file is already in use" errors, and deleting it when the program is definitely closed clears the problem.

## Converting it

A .lock file is commonly converted to .txt. It is a plain text format, so any text editor can open and edit it directly.

## Details

- **Extension:** .lock
- **Full name:** Lock File
- **Category:** Data
- **MIME type:** text/plain
- **Created by:** Various
- **Format:** Plain text

## Common questions

### How do I open a .lock file?

On Windows use Visual Studio Code; on macOS use Visual Studio Code; on Linux use Visual Studio Code. Either a dependency version record or a marker saying a file is in use.

### What is a .lock file?

Lock File. Two unrelated things use this extension. Package managers write lock files — yarn.lock, Cargo.lock, poetry.lock — recording the exact dependency versions installed, and those are plain text that belongs in version control.

### Can I convert a .lock file?

Yes. It is usually converted to .txt, either by exporting from one of the programs listed above or with a format converter.

## Related pages

- [.csv — Comma-Separated Values](https://atoneplace.net/file/csv/)
- [.json — JavaScript Object Notation](https://atoneplace.net/file/json/)
- [.xml — Extensible Markup Language](https://atoneplace.net/file/xml/)
- [.yaml — YAML Data File](https://atoneplace.net/file/yaml/)
- [.log — Log File](https://atoneplace.net/file/log/)
- [.torrent — BitTorrent Metainfo File](https://atoneplace.net/file/torrent/)
- [.dat — Generic Data File](https://atoneplace.net/file/dat/)
- [.vcf — vCard Contact File](https://atoneplace.net/file/vcf/)
- [.sql — SQL Script](https://atoneplace.net/file/sql/)
- [.ics — iCalendar Event](https://atoneplace.net/file/ics/)
- [.sqlite — SQLite Database](https://atoneplace.net/file/sqlite/)
- [.db — Generic Database File](https://atoneplace.net/file/db/)

## Sources

- Media Types Registry — IANA (https://www.iana.org/assignments/media-types/)
- Official vendor product documentation — At One Place (/about/)