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Sample Log File Download — Free Server Log Test Files

Download free sample server log files from 10KB to 50MB — Apache access log samples, Nginx log examples, JSON structured logs, error logs with stack traces, and syslog format. Built for DevOps engineers, SREs, and QA teams testing log parsers with ELK Stack, Splunk, Datadog, and Grafana Loki. Each test log file for parsing contains realistic timestamps, IPs, status codes, and user agents.

Generate custom LOG fileCreate up to 1GB locally in your browser

sample-10kb.log

10 KB

50 lines

Download
File details and verification
Filename
sample-10kb.log
Exact size
10,240 bytes
Displayed size
10 KB
Catalog status
Valid catalog fixture
SHA-256
84e0a9f98b4c42f92957e4d24395131d1afefa17fc0233937519ec1f58eda78e
Header signature
Not applicable (no stable header signature for this format)
Verified on
2026-08-10
MIME type
application/octet-stream
Lines
50
Note
apache-access-log
License
CC0 / Public Domain
Download URL
https://cdn.truefilesize.com/log/sample-10kb.log

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sample-100kb.log

100 KB

500 lines

Download
File details and verification
Filename
sample-100kb.log
Exact size
102,400 bytes
Displayed size
100 KB
Catalog status
Valid catalog fixture
SHA-256
aa04d8250d6f6594372888c189da3b72eb3dea6682f310a16b2306f7fc8dcf6d
Header signature
Not applicable (no stable header signature for this format)
Verified on
2026-08-10
MIME type
application/octet-stream
Lines
500
Note
nginx-log
License
CC0 / Public Domain
Download URL
https://cdn.truefilesize.com/log/sample-100kb.log

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sample-500kb.log

500 KB

2,500 lines

Download
File details and verification
Filename
sample-500kb.log
Exact size
512,000 bytes
Displayed size
500 KB
Catalog status
Valid catalog fixture
SHA-256
644a5db795ff31e92840948de3a7372574ccc1b38ee8481a22907eaff6f8e8a0
Header signature
Not applicable (no stable header signature for this format)
Verified on
2026-08-10
MIME type
application/octet-stream
Lines
2,500
Note
application-log-json
License
CC0 / Public Domain
Download URL
https://cdn.truefilesize.com/log/sample-500kb.log

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sample-1mb.log

1 MB

5,000 lines

Download
File details and verification
Filename
sample-1mb.log
Exact size
1,048,576 bytes
Displayed size
1 MB
Catalog status
Valid catalog fixture
SHA-256
390b2cec0d9762eab2693016f880b17f47b902e9efda5049abb76baafcd8c743
Header signature
Not applicable (no stable header signature for this format)
Verified on
2026-08-10
MIME type
application/octet-stream
Lines
5,000
Note
error-log
License
CC0 / Public Domain
Download URL
https://cdn.truefilesize.com/log/sample-1mb.log

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sample-5mb.log

5 MB

25,000 lines

Download
File details and verification
Filename
sample-5mb.log
Exact size
5,242,880 bytes
Displayed size
5 MB
Catalog status
Valid catalog fixture
SHA-256
e05b7229dd2470fa1a2766b9208748f4ea16a7b87cae25dbc8d31bb4aeefffc2
Header signature
Not applicable (no stable header signature for this format)
Verified on
2026-08-10
MIME type
application/octet-stream
Lines
25,000
Note
syslog-format
License
CC0 / Public Domain
Download URL
https://cdn.truefilesize.com/log/sample-5mb.log

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sample-10mb.log

10 MB

50,000 lines

Download
File details and verification
Filename
sample-10mb.log
Exact size
10,485,760 bytes
Displayed size
10 MB
Catalog status
Valid catalog fixture
SHA-256
9fbdfec41170211f07d1af051dac94875f1562e083bb676d84034408c5fdf106
Header signature
Not applicable (no stable header signature for this format)
Verified on
2026-08-10
MIME type
application/octet-stream
Lines
50,000
Note
combined-log
License
CC0 / Public Domain
Download URL
https://cdn.truefilesize.com/log/sample-10mb.log

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sample-50mb.log

50 MB

250,000 lines

Download
File details and verification
Filename
sample-50mb.log
Exact size
52,428,800 bytes
Displayed size
50 MB
Catalog status
Valid catalog fixture
SHA-256
08cec95591c31138977a579df6fe26f0dcc47bcf8c70d602648a23850bf0ce39
Header signature
Not applicable (no stable header signature for this format)
Verified on
2026-08-10
MIME type
application/octet-stream
Lines
250,000
Note
combined-log
License
CC0 / Public Domain
Download URL
https://cdn.truefilesize.com/log/sample-50mb.log

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sample-apache-access.log

200 KB

1,000 lines

Download
File details and verification
Filename
sample-apache-access.log
Exact size
204,800 bytes
Displayed size
200 KB
Catalog status
Valid catalog fixture
SHA-256
cf3723ab85194dbab0d646127b0ff19f1989b19a9e371b01493a2c711921b342
Header signature
Not applicable (no stable header signature for this format)
Verified on
2026-08-10
MIME type
application/octet-stream
Lines
1,000
Note
apache-combined-log-format
License
CC0 / Public Domain
Download URL
https://cdn.truefilesize.com/log/sample-apache-access.log

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sample-nginx.log

200 KB

1,000 lines

Download
File details and verification
Filename
sample-nginx.log
Exact size
204,800 bytes
Displayed size
200 KB
Catalog status
Valid catalog fixture
SHA-256
5464f7be1dfb0378b2fd2ec97a4fa2d2adb265052e11ae23b775cba96f933e9b
Header signature
Not applicable (no stable header signature for this format)
Verified on
2026-08-10
MIME type
application/octet-stream
Lines
1,000
Note
nginx-combined-format
License
CC0 / Public Domain
Download URL
https://cdn.truefilesize.com/log/sample-nginx.log

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sample-json-structured.log

300 KB

1,000 lines

Download
File details and verification
Filename
sample-json-structured.log
Exact size
307,200 bytes
Displayed size
300 KB
Catalog status
Valid catalog fixture
SHA-256
b8b9abdbfae729eb55f473e07bbcc609a90210ccf1c0419d58ca60b63949ec4f
Header signature
Not applicable (no stable header signature for this format)
Verified on
2026-08-10
MIME type
application/octet-stream
Lines
1,000
Note
json-structured-logging
License
CC0 / Public Domain
Download URL
https://cdn.truefilesize.com/log/sample-json-structured.log

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sample-error.log

150 KB

500 lines

Download
File details and verification
Filename
sample-error.log
Exact size
153,600 bytes
Displayed size
150 KB
Catalog status
Valid catalog fixture
SHA-256
f3ba5c15c83862188b4c4309b31bb67803f88da52c0a892635ffe95af81d96ed
Header signature
Not applicable (no stable header signature for this format)
Verified on
2026-08-10
MIME type
application/octet-stream
Lines
500
Note
error-log-with-stack-traces
License
CC0 / Public Domain
Download URL
https://cdn.truefilesize.com/log/sample-error.log

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sample-syslog.log

200 KB

1,500 lines

Download
File details and verification
Filename
sample-syslog.log
Exact size
204,800 bytes
Displayed size
200 KB
Catalog status
Valid catalog fixture
SHA-256
65af1ce08f0af09e4bff52f9d3456ab430cdb9720d6c37442e68a02ee008f671
Header signature
Not applicable (no stable header signature for this format)
Verified on
2026-08-10
MIME type
application/octet-stream
Lines
1,500
Note
syslog-rfc5424
License
CC0 / Public Domain
Download URL
https://cdn.truefilesize.com/log/sample-syslog.log

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Use cases for sample log files

  • Testing log parsing in ELK Stack (Elasticsearch, Logstash, Kibana)
  • Verifying Grafana Loki / Promtail log ingestion
  • Testing Splunk, Datadog, or New Relic log import
  • Benchmarking log parsing performance (grep, awk, jq)
  • Testing custom log parsers and regex patterns
  • Developing and testing log monitoring dashboards

Log format examples

Apache Combined Log Format

192.168.1.42 - john [15/Jan/2024:13:55:36 +0000] "GET /api/v1/users HTTP/1.1" 200 2326 "https://example.com/" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7)"

JSON Structured Log (pino/winston)

{"level":"info","time":"2024-01-15T13:55:36.000Z","pid":1234,"hostname":"api-3","msg":"Request completed","req":{"method":"GET","url":"/api/v1/users"},"res":{"statusCode":200},"responseTime":42}

Error Log with Stack Trace

[2024-01-15 13:55:36.123] ERROR: Connection refused to database
  ConnectionRefusedError: connect ECONNREFUSED 10.0.0.5:5432
    at TCPConnectWrap.afterConnect (net.js:1141:16)
    at Pool.connect (pool.js:88:12)

Syslog (RFC 5424)

<134>1 2024-01-15T13:55:36.000Z webserver-1 nginx 2847 - - 192.168.1.42 - - "GET /health HTTP/1.1" 200

Log format comparison

FormatParsingBest forIn our samples
Apache/Nginx CLFRegexWeb server access logsapache-access, nginx
JSON structuredJSON.parse()Application logs, ELKjson-structured
Error + stack traceMulti-line regexDebugging, error trackingerror
Syslog (RFC 5424)Standard parsersSystem/infrastructuresyslog
Combined (mixed)Format detection neededTesting auto-detection10MB, 50MB

How to parse log files

# Count requests by status code (Apache/Nginx)
awk '{print $9}' access.log | sort | uniq -c | sort -rn

# Extract all 5xx errors
grep '" 5[0-9][0-9] ' access.log

# Parse JSON structured logs with jq
cat app.log | jq -r 'select(.level == "error") | .msg'

# Count errors per hour
cat app.log | jq -r '.time[:13]' | sort | uniq -c

# Logstash grok pattern for Apache
grok { match => { "message" => "%{COMBINEDAPACHELOG}" } }

# Python log parsing
import re
pattern = r'(S+) S+ S+ [(.+?)] "(S+) (S+) S+" (d+) (d+)'
for line in open('access.log'):
    match = re.match(pattern, line)
    if match: print(match.groups())

Technical specifications

Extensions.log, .txt, .out
EncodingUTF-8 (line-delimited)
Apache formatCombined Log Format (CLF)
JSON formatNDJSON (newline-delimited JSON)
Syslog standardRFC 5424
ContentRealistic IPs, timestamps, user agents, status codes

Frequently Asked Questions

What is a log file?
A log file is a text file that records events, errors, and activity from software, servers, or operating systems. Each line typically contains a timestamp, severity level, source, and message. Web servers (Apache, Nginx) log every HTTP request. Applications log errors, warnings, and debug information. System logs (syslog) track OS-level events. Log files are essential for debugging, monitoring, security auditing, and performance analysis.
Apache log format explained — What is Combined Log Format?
Apache Combined Log Format (CLF) is the standard web server access log: IP - user [timestamp] "METHOD /path HTTP/1.1" status bytes "referer" "user-agent". Example: 192.168.1.42 - john [15/Jan/2024:13:55:36 +0000] "GET /api/users HTTP/1.1" 200 2326 "https://example.com/" "Mozilla/5.0...". Our sample-apache-access.log contains 1000+ realistic entries in this format for testing Logstash grok patterns and custom parsers.
How to parse log files?
CLI: grep, awk, sed for quick filtering. Structured: jq for JSON logs (cat app.log | jq '.level'). Regex: Python re module or Logstash grok patterns (%{COMBINEDAPACHELOG}). Tools: ELK Stack (Elasticsearch + Logstash + Kibana), Splunk, Datadog, Grafana Loki + Promtail. Our sample files include all major formats so you can test each parsing approach.
Structured vs unstructured logs — What is the difference?
Unstructured logs are human-readable text lines (Apache/Nginx CLF, error logs with stack traces) — parsed with regex or grok patterns. Structured logs are machine-readable JSON objects (one JSON per line, NDJSON) — parsed with JSON.parse(), used by pino, winston, bunyan. Structured logs are easier to query and index but harder to read. Our samples include both types for testing.
What log formats are included in these samples?
Five formats: (1) Apache Combined Log Format — standard web server access log. (2) Nginx logs — with upstream response timing. (3) JSON structured — NDJSON as produced by pino/winston/bunyan. (4) Error logs — with multi-line stack traces. (5) Syslog RFC 5424 — Linux system log. Plus combined files (10MB, 50MB) that interleave all five formats for testing auto-detection.
Can I use these logs with ELK Stack, Splunk, or Grafana Loki?
Yes. Apache/Nginx logs work with Logstash grok patterns (%{COMBINEDAPACHELOG}). JSON structured logs ingest directly into Elasticsearch. Syslog logs work with rsyslog/syslog-ng. For Grafana Loki, use Promtail with pipeline stages matching each format. For Splunk, use the standard source types (access_combined, syslog).

Other data formats

JSONCSVTXTYAML

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