Are the IP addresses real?

No. They come from the address ranges that RFC 5737 reserves for documentation, so they belong to no one.

What is the MIME type of a LOG file?

The MIME type is text/plain. The file extension is .log.

Is a sample LOG file the same as a dummy or example LOG file?

Yes. Sample, test, dummy and example LOG files are different names for the same thing: a LOG file with known contents that stands in for a real one. Any file on this page will do wherever a tutorial or a test plan asks for a dummy LOG file.

Free LOG sample files

Line-oriented text records of events. The samples use the web-server Combined Log Format. Download valid LOG test files in 6 exact sizes, from 1 KB to 10 MB, each with a checksum.

Extension: .log
MIME type: text/plain
Kind: Text
Category: Testing

LOG files by size

Every file below is a valid Log file file of exactly the stated size. Open a file's page for its checksum and contents, and to preview it in your browser before downloading.

LOG sample files by size
File	Size	Contents	Download
1 KB LOG samplesample-log-1kb.log	1 KB1,024 bytes	Lines: 7	Download LOG
10 KB LOG samplesample-log-10kb.log	10 KB10,240 bytes	Lines: 64	Download LOG
100 KB LOG samplesample-log-100kb.log	100 KB102,400 bytes	Lines: 627	Download LOG
1 MB LOG samplesample-log-1mb.log	1 MB1,048,576 bytes	Lines: 6,411	Download LOG
5 MB LOG samplesample-log-5mb.log	5 MB5,242,880 bytes	Lines: 31,986	Download LOG
10 MB LOG samplesample-log-10mb.log	10 MB10,485,760 bytes	Lines: 63,820	Download LOG

More LOG samples

Hand-designed files with realistic content or a specific edge case.

Curated LOG sample files
File	Size	Contents	Download
Sample web server access log (500 lines)sample-access.log	80.2 KB82,141 bytes	Lines: 500	Download LOG

What is a LOG file?

A log file records events as lines of text, typically one per event, appended in time order. The layout depends on the software that wrote it.

The samples follow the Combined Log Format written by Apache and nginx: client address, timestamp, request line, status code, response size, referrer and user agent.

How to recognise a LOG file

No signature bytes. LOG files are identified by parsing their content.

Extension	.log
MIME type	text/plain
Layout	Combined Log Format
Encoding	ASCII or UTF-8
Record separator	Line feed
Growth	Append-only; rotated and compressed by tools such as logrotate

What to test for

These are the behaviours that most often go wrong when software handles LOG files.

Request paths and user agents come from clients and may contain quotes or escape sequences; a pattern that assumes clean input will misparse real traffic.
Timestamps carry a zone offset. Parsers that drop it shift every event.

Strengths of LOG

Human-readable and easy to search with standard command-line tools.
Append-only, so writing is cheap and safe.

Limitations of LOG

No schema: every consumer needs its own parsing rules.
Free-form fields make reliable parsing harder than structured logging.

Typical uses of LOG test files

Testing log parsers and grok patterns
Checking dashboards and alert rules
Benchmarking ingestion pipelines

Software that opens LOG

tail, grep, awk and less
GoAccess, Logstash, Fluent Bit and Vector
Splunk, Elasticsearch and Grafana Loki

Specifications

LOG sample files: questions

Are the IP addresses real?: No. They come from the address ranges that RFC 5737 reserves for documentation, so they belong to no one.
What is the MIME type of a LOG file?: The MIME type is text/plain. The file extension is .log.
Is a sample LOG file the same as a dummy or example LOG file?: Yes. Sample, test, dummy and example LOG files are different names for the same thing: a LOG file with known contents that stands in for a real one. Any file on this page will do wherever a tutorial or a test plan asks for a dummy LOG file.