In addition to Screaming Frog, which is very well-known in the industry, you may also be interested din Sitebulb, which seems to have been inspired by Screaming Frog but took a slightly different approach to the presentation of the audit information.
Yep - Screaming Frog (desktop tool) has a limit of 500 pages in the free version, which is probably enough for most smaller-sized websites.
In terms of web-based tools, VisualSitemaps.com also has a freemium option with a 50 page limit.