The short answer: every builder here lets you get the code out, through GitHub or a zip. The database and backend are where lock-in sits. Lovable on your own Supabase and Bolt with GitHub give the most standard exits; Base44 needs a rebuild of data and backend calls; v0 is a front-end tool tied to Vercel for deployment. Lovable Cloud has no one-click move to your own Supabase.
The matrix
Each cell is from the vendor’s own docs, read on 29 September 2026. “Not documented” marks a question the docs we read did not answer. We read docs; we did not export a live project from each tool.
| Attribute | Code out | Database and backend out | Hosting exit | Cost of leaving |
|---|---|---|---|---|
| Lovable | Two-way GitHub sync; direct code download on paid plans (custom domains and code export are Pro and above) | Data on your own Supabase is standard Postgres. On Lovable Cloud you export data, connect Supabase to a new project and rebuild the schema; edge functions and auth users are not listed as exportable | Repository stays intact on GitHub if you disconnect | Low on Supabase; a manual rebuild on Cloud |
| Bolt.new | GitHub sync keeps a full history outside Bolt; you can work in GitHub and come back | Bolt Cloud databases are managed by Supabase per Bolt’s announcement; export of that data is not documented | Publish with Bolt hosting, Netlify or another service you choose | Low for code; database exit not documented |
| v0 | GitHub sync to a repository with branches and pull requests | Not documented in the GitHub docs page | Built for Vercel; v0’s docs say GitHub sync “does not grant permission to deploy through GitHub or other Vercel interfaces” | Front-end code exits cleanly; you bring your own backend |
| Base44 | GitHub integration on Builder and above; eject copies frontend and backend definitions to a local project | CSV export per table; ejected project starts with an empty database; backend functions are written against Base44’s SDK | Not documented | Medium to high: re-point the backend and re-import data |
| Replit Agent | Download as zip from the file tree; GitHub connect with two-way auto-sync | Database export not documented; production databases are billed by Replit | Deployments are Replit-hosted and billed for data transfer and compute | Code is easy; data path unclear |
| Atoms.dev | Not documented in the help centre we could read | Not documented | Not documented | Unknown; ask support before committing |
The Base44 and Lovable cells match our earlier analysis in Base44 vs Lovable. The Base44 SDK point is our reading of its docs, not a Base44 statement.
What “lock-in” means in practice
Code is rarely the problem. A repository from any of these tools is text you can read. Three things are:
- Data. A managed database you cannot dump is the real hostage. Check you can export every table and the auth users before you have customers.
- Backend calls. Base44’s SDK and Lovable Cloud’s functions run on their platform. Moving means rewriting those calls.
- Credits as a gate. If your live backend pauses when credits hit zero, you are locked to keeping a balance, not just a vendor. See what happens when credits run out.
Pick by exit need
| If you need… | Lean towards | Why |
|---|---|---|
| A standard stack you can hand to any developer | Lovable with your own Supabase (why) | Postgres and GitHub, both portable |
| Code in Git with hosting of your choice | Bolt.new | Docs explicitly allow other hosts |
| A UI you will wire to your own backend | v0 | GitHub sync; Vercel deployment |
| An internal tool where a managed backend is the point | Base44 | Accept the rebuild cost if you leave |
| Everything in one place, exit unlikely | Replit | Zip download exists; check database plans first |
The head-to-head with costs sits in Lovable vs Bolt vs v0; the broader shortlist is best AI app builder.
Method
Researched from vendor documentation on 29 September 2026. This is a docs comparison: we have not exported a production app from each tool, and docs can lag the product. Cells marked “not documented” are gaps in what we read, not statements that the feature is missing. Due for re-check every 60 days.
Common questions
Can I export my Lovable code?
Yes. Lovable syncs to GitHub two-way and offers code download on paid plans. Free plans do not include code editing or download per the pricing index.
Can I leave Lovable Cloud for my own Supabase?
Not with one click. Lovable’s docs describe exporting your Cloud data, connecting a Supabase project to a new Lovable project and rebuilding the schema there.
Which builder has the least lock-in?
For code, all of them are close. For the backend, a Supabase-backed Lovable or Bolt project has the most standard exit; Base44 has the most platform-specific one.