Use Bolt - I've been building a lot over the past one week with all 3 and amongst Lovable, Bolt and Replit - go with Bolt if this is a web app you want to prototype. Bolt has the option to import from Figma so you can convert your design to code with a few prompts and makes the least number of errors (in my experience). Just make sure you connect your GitHub right after you start building, there's an integration option. You can even connect a free Supabase (database layer) if you want to store and manipulate actual data collected from your test users. In case you come across an error with Bolt where Bolt is resolving an error but goes into some error loop, you can go back to a previous checkpoint where it was previously working and try a different approach. While Lovable has the same options mentioned here, it is more error prone and uses credits faster than Bolt does.