Which is the best tool to analyze server log file?

[AshokS]

To analyze crawl budget, 4xx and 5xx errors and crawl rate?

[TomRayner]

You can't beat the SEO Log File Analyser from Screaming Frog, imo:

https://www.screamingfrog.co.uk/log-file-analyser/

[ThompsonPaul]

Another +1 for Screaming Frog's Log File Analyzer. (It's a separate tool from their superb Crawler tool.)

Paul

[JordanLowry]

This depends on the size of your site. In some instances, you can just use excel to analyze your server logs. Or if you have the resources you can use a paid tool like the SEO Log File Analyser from Screaming Frog.

Here are some resources from Moz that might be helpful for you:

https://moz.com/blog/uncovering-seo-opportunities-via-log-files

https://moz.com/blog/technical-seo-log-analysis

However, if you have a large site you might run into some issues using excel or Screaming Frog's tool.

With a larger site, you might be better served either looking at a small subset of the data or using an enterprise analytics tool like Altreyx or Knime to do your analysis.