What Is a .log File? .log Format, MIME & How to Open

Quick facts

Extension.log

File typeLog File

MIME typetext/plain

CategoryData & Text

Charset—

CompressibleYes

Format familylog

What is .log

What is a .log file?

A .log file is a Log File — Plain-text log of application or system events.

In the mime-db registry it maps to text/plain, and it is marked as compressible. When serving .log over HTTP, set the Content-Type header as shown in Developer info below.

Related entities: it maps to text/plain — and is delivered over HTTP via the Content-Type header.

How to open .log files

Use VS Code or tail to open and edit .log files.
Any text editor (Notepad, VS Code) can inspect the raw content as text.

Developer info

When served over HTTP, responses should set the following header:

Content-Type: text/plain

Common software that reads/writes .log:

VS Codetail

Relation chain

.logextension of

format

logserved as

mime type

text/plainsent via header

http header

Related extensions

Related MIME types

Common uses

Configuration files
Data interchange between systems
API request and response payloads
Logs and data exports

How to edit .log files

Open the file with VS Code, make your changes and save.
Most editors preserve the original formatting and encoding — avoid changing the charset.

How to create .log files

Create a new file and save it with the .log extension, or export this format from VS Code.

Frequently asked questions

What programs can open .log files?

Common options include VS Code, tail. You can also open many of these files with built-in viewers or a browser.

How do I create a .log file?

Create a new file in any text editor or the app that owns the format and save it with the .log extension.

What is the relationship between .log and the text/plain MIME type?

text/plain is the media type identifier used for .log files during network transfer (for example in the HTTP Content-Type header).

Sources & standards

Updated 2026-09-13

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