What is an AI app builder, and what does one build?
An AI app builder turns a plain-language description into a working web app: it writes the pages and the logic, creates a database and sign-in, hosts the result and gives you a URL, with no code written by you. Lovable, Bolt.new, v0, Base44 and Replit are the full-stack kind. The pages ranking for the term explain this in prose and show no build. This one adds 6 measured runs on one builder, 30.4 credits in total, and links every comparison on the site.
The definition
Three definitions agree on the shape
“a platform that lets you create fully functional apps using plain language”
“a full-stack AI development platform for building, iterating on, and deploying web applications”
“a software platform that uses artificial intelligence to automate large parts of application development”
Two things separate the category from what came before it. Against no-code, the builder writes code instead of assembling blocks, so the output is a codebase that syncs to GitHub. Against a coding agent such as Cursor, the builder owns the stack from editor to hosting, so there is no server to set up, and on Lovable and Base44 no existing repository you can bring.
How it works
From a prompt to a published app in six steps
The sequence observed on every measured run here. The backend step happens the first time the app needs to store something; on Lovable, Cloud usage is metered separately from the build.
- 01
Prompt
Who uses it, what it does, the rules
- 02
Questions
If the prompt asks for them
- 03
Build
Pages, logic, a plan first if asked
- 04
Backend
Database and auth, on first need
- 05
Preview
Click through, the builder self-tests
- 06
Publish
A URL, then your domain
The questions step is the one a prompt controls. The runs whose prompt ended by asking for questions drew 11 of them before building, and the runs without that line drew none. The prompting guide explains the line, and the prompt library carries it on every brief.
The five kinds
Five kinds of tool use the same label
Sorted by what you own afterwards. The last column sends you to the comparison that answers the choice.
| Kind | Examples | What it produces | What you own | Read next |
|---|---|---|---|---|
| Full-stack web builder | Lovable, Bolt.new, v0, Base44 | A web app with a database, auth and hosting from a prompt | Source code, synced to GitHub; Base44's frontend still calls its servers | Compare → |
| Cloud IDE with an agent | Replit | The same, inside a workspace with a shell and Git | The repository | Compare → |
| Coding agent in an editor | Cursor, Claude Code | Changes to a repository you already have | Everything; it is your repo | Compare → |
| Visual no-code builder | Bubble | An app assembled from blocks, AI-assisted | Nothing exportable: apps run only on Bubble | Compare → |
| Form and template builder | Jotform, Choicely | Data-collection or store-published apps from templates | Data and app on the vendor's platform | Compare → |
What one built, measured
6 runs on one builder, 30.4 credits
The vendor pages promise minutes and show no build. These are every Lovable run measured on this site, each linked to the page with its screenshots. The shape transfers across builders: a review costs little, a screen costs some, a foundation with auth and roles costs most.
Each bar is one run, read from the workspace credits page before and after. Rose bars are runs whose prompt asked the builder to ask questions first.
| Run | Date | Credits | Questions asked first |
|---|---|---|---|
| SEO review, no code | 26 Sep 2026 | 1.1 | 0 |
| Landing page + opt-in | 31 Jul 2026 | 1.8 | 0 |
| Installable PWA | 26 Sep 2026 | 3.1 | 0 |
| SaaS landing page | 26 Sep 2026 | 4.5 | 5 |
| Empty states + skeletons | 26 Sep 2026 | 9.5 | 2 |
| SaaS MVP with auth | 26 Sep 2026 | 10.4 | 4 |
6 runs, 30.4 credits in total, 31 July and 26 September 2026, our own workspace. 11 questions were asked across the 3 runs whose prompt asked for them, and none in the rest. No other builder was run.
- 31 Jul 2026Landing page + opt-in: One round, all five priority features, inline success state, Cloud enabled
- 26 Sep 2026Empty states + skeletons: Asked 2 questions, built a /states gallery and a task list, verified slow load, failure and retry
- 26 Sep 2026SaaS MVP with auth: Asked 4 questions, enabled Cloud, self-tested sign-up and invites, roles checked in the database
- 26 Sep 2026SEO review, no code: 5 of 6 checks passing; the sitemap deferred until publish
- 26 Sep 2026Installable PWA: Manifest, icons, service worker, Add to Home Screen; verified in the preview
- 26 Sep 2026SaaS landing page: Five questions first, six minutes to a preview; server-rendered, FAQ schema, one CTA
Which comparison to read
Your question, and the page that answers it
Which builder should I start on?
Six builders on one brief, one measured
Best AI app builder →
Should I stay on Lovable or leave?
Six tools, the case for staying first
Lovable alternatives →
Lovable or Bolt?
Credits against tokens; only Bolt imports a repo
Lovable vs Bolt →
Lovable or Replit?
A builder or a workspace with a shell
Lovable vs Replit →
Lovable or Cursor?
One builds the app, one edits the code
Lovable vs Cursor →
Lovable or v0?
React on Lovable Cloud or Next.js on Vercel
Lovable vs v0 →
Lovable or Base44?
Which plan gets GitHub, and what the export still needs
Lovable vs Base44 →
Lovable or Bubble?
Code you own or an app that runs only on Bubble
Lovable vs Bubble →
Leaving Replit?
Sorted by the job Replit did
Replit alternatives →
Leaving Base44?
Sorted by what you keep
Base44 alternatives →
Leaving Bolt.new?
Sorted by why you leave
Bolt.new alternatives →
Leaving v0?
Sorted by the job v0 did
v0 alternatives →
Is Lovable any good?
Measured builds, ratings and the record
Lovable review →
What does a Lovable build cost?
Plans read on the day, builds per plan
Lovable pricing →
What none does yet
Six things the builders cannot do, per their own docs
| Limit | What the docs say | Source |
|---|---|---|
| Open an existing codebase | Lovable and Base44 cannot: Lovable's Git sync always creates a new repository, Base44's syncs out from its own app. Bolt, v0 and Replit import one. | Lovable GitHub docs |
| Work on several branches at once | Lovable edits and syncs one branch at a time; Bolt cannot merge branches in-app; Base44 needs a branch named main. | Bolt Git docs |
| Run without the vendor | An exported Base44 frontend still calls Base44's servers for every read and login, per a July 2026 migration guide; Lovable Cloud apps pause at a zero credit balance. | 13Labs, 29 July 2026 |
| Print a price per prompt | No builder does. Lovable prints examples from 0.50 to 2.00 credits; Bolt says project size sets the token cost; Replit bills effort per checkpoint; v0 says tokens per credit depend on the model. | Lovable credits docs |
| Ship a native store app | A Lovable build runs on a phone as a web app or an installable PWA; our PWA run added a manifest, icons and a service worker. A store app needs a wrapper or a native builder. | Our PWA run |
| Be secure by default | Insufficient row-level security in generated Lovable projects has a CVE (CVE-2025-48757); the fix that holds is stating who can read and write what in the prompt and testing it as the wrong user. | The Next Web |
The last row is the one to act on. The security guide shows the scan we ran on our own project, and the build kits ship schemas whose policies were executed as a member and as an admin before any screen.
Try one with a prompt that works
Lovable's Free plan gives 5 build credits a day, no card. The cheapest run above cost 1.8 of them.
What we did not publish
- Runs on any builder but Lovable. Every other builder on this page is its documentation with a read date.
- Market-size figures that circulate on vendor blogs: none traced to a primary source.
- User counts and template counts from vendor pages, such as Base44's builder count: they could be checked against nothing but the page that makes them.
- Build times as a measure: the credits page records credits, not minutes.
Frequently asked
What is an AI app builder?
A platform that turns a plain-language description into a working application: it generates the interface and the logic, provisions a database, authentication and hosting, and publishes to a URL, without you writing or deploying code. Lovable, Bolt.new, v0, Base44 and Replit are the full-stack kind; form builders and native mobile builders use the same label for narrower products.
How is an AI app builder different from no-code?
No-code tools give you a visual editor and a fixed set of blocks, and you assemble the app. An AI app builder writes code from a prompt, so the result is a codebase, and the full-stack builders sync it to GitHub. A no-code app cannot do what its blocks cannot; an AI-built app can do anything code can, including things you did not ask for.
How is an AI app builder different from Cursor or Claude Code?
A coding agent works on a repository you already have and leaves the database, auth and hosting to you. A full-stack builder owns the whole stack from editor to hosting. Some builders now import a repository too: Bolt, v0 and Replit do, Lovable and Base44 do not, per their docs read 23 October 2026.
How much does an AI app builder cost to use?
What it cost on one builder: the 6 runs measured on this site took 30.4 Lovable credits together, from a review that changed no code to a SaaS foundation with auth and invites at 10.4, each read from the billing page. Lovable Pro was €25 a month for 100 credits on 22 October 2026. The other builders' plans are priced on the comparison pages with their read dates.
Can an AI app builder make a mobile app?
A web app that runs on a phone, yes, and an installable one: our PWA run added a manifest, icons and a service worker to a Lovable app, verified in the preview. A store-published native app is a different product, reached through a wrapper or a native builder.
Are AI app builders secure?
Not by default, on the record. Insufficient row-level security in Lovable-generated projects has a CVE, and an April 2026 disclosure covered an authorisation flaw in Lovable's own API. The builders ship security scanners now. The fix that holds is in the prompt and the database: state who can read and write what, and run a query as the wrong user before anyone signs up.
Sources, with the date each was read
- Base44: definition 23 October 2026
- Lovable: definition 23 October 2026
- IONOS: definition 23 October 2026
- Lovable credits and usage 23 October 2026
- Lovable GitHub integration 23 October 2026
- Bolt Git docs 23 October 2026
- Replit billing docs 23 October 2026
- v0 Git import docs 23 October 2026
- cursor.com/pricing 23 October 2026
- 13Labs on Base44 exports, 29 July 2026 23 October 2026
- The Next Web on Lovable's record 26 September 2026
Written by
Marco Kohns
Founder of ProtoBites - Venture Growth Studio
Growth PM at a Silicon Valley scale-up (a16z and General Catalyst backed), ex-Techstars where he consulted 13 early-stage startups, Reforge-trained. Every prompt on this site comes out of shipping ProtoBites' own portfolio products.
Related reading
- best AI app builder · One tested, six priced on the same day.
- Lovable alternatives · When to stay and when to leave, by what you keep.
- the Lovable app builder, panel by panel · Build, Plan and Chat modes with our runs.
- whole-app prompts · Briefs with a build order, for a full app.
- Lovable vs Bolt · Two prompt-to-app builders, facts checked on one day.
- Lovable vs Replit · Builder against cloud IDE with an agent.
- Base44 alternatives · Its plans and GitHub rules quoted.
- Lovable pricing · Plans read on the day, with the check date.
- Lovable mobile app · What runs on a phone and what needs a wrapper.
- what is vibe coding · The practice the builders exist for.
- Lovable vs Base44 · Two managed backends compared.
- Lovable vs Bubble · Prompt-to-code against a visual builder with an agent.
- v0 alternatives · For apps from prompts or UI in your repo.
- Bolt alternatives · Sorted by the reason you leave.