Example (here using the IP address where SL is running, this one only works via LAN, not WWW):

http://192.168.0.22/ 

If you have no local network, but want to test the server locally, use IP address 127.0.0.1 which always 'loops back' to the local machine.
Both server ('host') and client (your web browser) can run on the same PC then.
If the above link doesn't work even though SpecLab is running, the most likely reason is that SL's built-in web server is disabled (which it is, by default, for security) or because windows or the windows firewall has blocked it.

At the time of this writing, the HTTP server in SpecLab allows you to...

• show the current spectrogram, sent to your browser as .jpg or .bmp file,
• show the waterfall colour palette, also as jpg or bmp,
• display the colour legend for the Radio Direction Finder,
• retrieve FFT data from the spectum display buffer (example: fft_expt.html)
• call any interpreter function inside SL to show the display in your browser,
• execute any interpreter command inside SL (see manual on "interpreter commands").

• Back to the main page with the spectrogram
• Details about SpecLab's built-in HTTP server
  Contains all information which you need to write your own 'user interface' for Spectrum Lab, either locally or remotely controlled.
  
• Using OpenWebRX as an alternative for SL's server pages