1. Lovable— free tier available, from $25/mo
An AI software engineer you chat with: describe a web app and it writes, previews and deploys it, with Supabase and GitHub wired in.
Lovable is the best pure chat-to-app builder for founders, and if you have already validated your idea it is a better use of $25 than almost anything else. Its blind spot is structural rather than technical: it will build the wrong product as beautifully as the right one, because nothing in the product asks whether anyone wants it. kitty.build answers that question first — nine boards, live research, a cited verdict that is allowed to say no — and then builds and operates the survivor. If you are certain about the idea, use Lovable. If you are certain because you like the idea, validate it first.
- Best at:
- The fastest path from a sentence to a working, good-looking web app in this whole set
- Watch out for:
- Credits burn fastest when you are debugging, which is exactly when you can least afford it
- Best for:
- Founders who already know what to build and want the fastest, prettiest path to a working web app.
- Pricing:
- Free $0 · Pro $25/mo · Business $50/mo · Enterprise Custom
Read the full kitty.build vs Lovable comparison →
2. Bolt.new— free tier available, from $25/mo
StackBlitz's in-browser AI app builder: prompt it and a full-stack app is written, run and deployed without leaving the tab.
Bolt.new is the best free way to find out whether an app idea is buildable, and the token rollover on Pro is the fairest metering in the builder category. What it does not do — like every builder here — is tell you whether the thing is worth building; it will happily burn 10M tokens on a product with no market. Use Bolt to answer "can this be built and how hard is it". Use kitty.build to answer "should it be", and then to keep the answer alive after launch with a site on your domain, code in your repo and daily operating cycles.
- Best at:
- The most generous free tier of any AI app builder here — 1M tokens/month without paying
- Watch out for:
- Tokens are consumed by failed attempts, so error loops are expensive
- Best for:
- Prototypers who want to try five app ideas this week without paying, and who are comfortable steering an AI through the rough edges.
- Pricing:
- Free $0 · Pro $25/mo · Teams $30/member/mo · Enterprise Custom
Read the full kitty.build vs Bolt.new comparison →
3. Bubble— free tier available, from $29/mo (annual)
The most mature visual no-code platform: build complex web apps by dragging elements and wiring workflows, with a deep plugin ecosystem behind it.
Bubble is the grown-up of the no-code category: a decade of production apps, real logic depth, and a hiring market you can actually recruit from. Its costs are the least predictable of anything here — workload units meter every query, workflow and page load, and overage bills immediately — and there is no code export, so the app cannot leave. kitty.build is not a visual editor and does not try to be; it validates the idea first and then produces real code in your own GitHub repo. Choose Bubble for depth and permanence, kitty.build for judgement and ownership.
- Best at:
- The most capable no-code platform for complex, stateful applications — nothing else here comes close on logic depth
- Watch out for:
- Workload-unit pricing is the least predictable model in this comparison — overage starts at $0.30 per 1,000 units the moment you exceed the tier
- Best for:
- Founders building a genuinely complex, logic-heavy app who are willing to learn a professional tool and want a hiring market behind it.
- Pricing:
- Free $0 · Starter $29/mo annual · Growth $119/mo annual · Team $349/mo · Overage $0.30 / 1,000 WU
Read the full kitty.build vs Bubble comparison →
4. Replit— free tier available, from $20/mo ($17 annual)
A browser IDE with an AI Agent that builds, runs, hosts and databases your app in one place — the most developer-complete platform in this set.
Replit is the most complete build platform in this comparison and the only one where you can take the wheel from the agent mid-build without exporting anything. That completeness is also its shape: it is a development environment, and it assumes you have already decided what to develop. kitty.build assumes the opposite — that the expensive mistake is building the wrong thing — so it validates with nine researching boards first, then builds, then runs the venture. Technical founders who already know their idea is good will get more out of Replit.
- Best at:
- The most complete platform here: you never leave for a database, a host or a terminal
- Watch out for:
- Model credits are consumed on top of the subscription, so the real monthly cost is variable
- Best for:
- Technical founders who want an agent and a real development environment in the same place, and who will read the code it writes.
- Pricing:
- Starter $0 · Core $20/mo ($17 annual) · Pro $100/mo ($95 annual) · Enterprise Custom
Read the full kitty.build vs Replit comparison →
5. kitty.build— free tier available, from $17/mo
An AI co-founder that validates an idea with nine researching boards, then builds, ships and runs the venture that survives.
kitty.build is the only tool in this set that both refuses to build a bad idea and builds the good one. Nine boards research the live web, cite what they find and return a GO / PIVOT / NO-GO verdict for free; if the verdict is GO, the same product ships the site on your domain, writes the code into your GitHub repo and runs daily cycles where a task only counts as done with evidence attached. The trade is that it is a subscription and it is opinionated. If you want a single document, or you want to art-direct every pixel yourself, something else on this list fits you better.
- Best at:
- The first verdict is free and it is allowed to say no
- Watch out for:
- It is a subscription — if you only want one document and then silence, a one-time report is cheaper
- Best for:
- Solo founders and small teams who want the idea checked honestly first, and the surviving one actually built and operated without hiring.
- Pricing:
- Free $0 · Spark $17/mo · Portfolio $66/mo · Studio $166/mo