FSIISLogViewer · for Windows servers running IIS

Who is knocking at your server?
Your IIS logs know.

Every web server on the internet gets probed daily – for old admin pages, vulnerabilities and passwords. FSIISLogViewer makes IIS log files readable: filter, search, hide the noise and see who really comes by.

Download for free See the features

Free · Windows with .NET Framework 4.8 · no installation

FSIISLogViewer showing one day of requests, filtered by status code
One day of requests, filtered and searchable

Web and FTPW3SVC and FTPSVC logs, local or on the network.

FiltersInclude and exclude lists, full text and regex.

OriginCountry per IP address and an RDAP lookup in one click.

Features

Log files you can actually read

Pick a log folder

Recently used folders with website, number of files and last update; plus folders of your own and network folders.

One day or everything

Analyze the selected day or every log file of a folder; the distinct list shows each value of a column only once.

Search

Full text or regular expressions, optionally in one particular column.

Include and exclude

Right-click to put a value on the include or exclude list, for instance your own IP address or a known attacker.

Hide the noise

Hide common requests and file types such as images, scripts or stylesheets with one click.

Spot bots

Crawlers, monitoring services and scripts are recognized by their user agent and told apart from real visitors.

Origin and IP lookup

The country of every IP address from the free DB-IP database, plus an RDAP lookup (the successor of WHOIS) for the network owner.

Fields explained

Tooltips explain every column, HTTP status codes and Windows error codes; unusual responses stand out right away.

The analysis runs entirely on your computer. Only the RDAP lookups you trigger and the download of the country database go to the internet. IP geolocation by DB-IP (db-ip.com), licensed under CC BY 4.0.

Requirements

What you need

  • Windows with .NET Framework 4.8 – already included in Windows 10 and 11 and current Windows Server versions
  • Read access to the IIS log folders (usually C:\inetpub\logs\LogFiles)
  • Log files in W3C format, the IIS default
  • The program itself is in English

Download

Download FSIISLogViewer

Free of charge. Unzip and start FSIISLogViewer.exe – no installation needed.

ZIP file for Windows · version 1.2610.18.3

Questions or wishes? Get in touch.