FAQ

What is this?

Trail is a free and open-source web application to display server access log files in a human-friendly way.

It can be useful if you want to:

• Investigate bugs or incidents in your web application
• Learn more about how people use your site
• Proactively find issues

What is it not?

Trail is not a web analytics tool. If you want to calculate aggregate traffic statistics based on your logs, great FOSS tools already exist for that, such as GoAccess and Matomo.

Why was this created?

Because all log viewers I found need to be downloaded, paid for, or most often both. Using Trail, on the other hand, is as easy as dropping a log file into your browser.

What are the limitations?

Browsers aren't best platform to process huge amounts of data, so Trail can only comfortably deal with logs of up to a certain size. This is roughly 50 MB, or 50.000 entries. However, you can use the filters on the home page to make larger logs manageable by discarding at load-time the entries you are not interested in.

What log formats are supported?

Currently only the combined log format (nginx, Apache, etc) and the AWS Cloudfront format. Adding new formats is quite simple, so more may be incorporated in the future.

Are logs uploaded anywhere?

No, all log processing is done within your own browser. Your logs aren't sent anywhere.

I have another question

Feel free to contact me or open an issue on GitHub.