Do Lovable, Bolt, Base44 and v0 train AI on your app? Defaults and how to opt out
All four AI app builders we test can use what you build to train AI models by default. Two of them let anyone switch that off for free. Here is each one's default, who can opt out, and exactly where the switch is, from each vendor's own docs.
The short answer: Bolt and Lovable train on your content by default but give every user a free off switch in account settings. Base44 has no opt-out below Enterprise. v0 lists the opt-out only on its Business ($100 per user a month) and Enterprise plans Reported. If your prompts or code include anything private, switch training off before you build: Lovable and v0 both say content already used for training isn't pulled back out Reported.
At a glance
| Tool | Trains on your content by default? Reported | Can you opt out? | Where the switch is |
|---|---|---|---|
| Bolt | On (may train) Off by default for accounts based in the EU, UK or Switzerland. | Yes, on every plan | Avatar (left sidebar) → Settings → General → Model training. Turn it off. |
| Lovable | On for Free and Pro (may train) Business and Enterprise workspaces are excluded by default. | Yes, free, Free and Pro plans | Account settings → Preferences → AI model training. Turn off "Use my Lovable content for model training". Direct link: lovable.dev/settings/account#privacy |
| Base44 | On for every plan except Enterprise (may train) Includes Business. | No setting | There is no opt-out to switch on. Only Enterprise workspaces are excluded, automatically. |
| v0 | On (may train) v0 Enterprise content is excluded. | Business ($100/user/month) and Enterprise, per v0's plan table | Vercel team settings → Data preferences (v0's FAQ links vercel.fyi/team-data-preferences). v0's plan table lists "Data Opt-out" as No on Free, Premium and Plus. |
This is what each vendor says in its docs. We haven't tested whether any of them honours its setting, and policies change, so check the linked page before you rely on it.
Bolt
- Default: On (may train). Off by default for accounts based in the EU, UK or Switzerland. Reported
- Opt out: Yes, on every plan. Avatar (left sidebar) → Settings → General → Model training. Turn it off. Reported
- What it covers: Your projects and chats. Applies to content you create on or after 7 Oct 2026, including older content you send to Bolt's AI after that date. Reported
- Watch out for: Bolt Forge (its open-source-model agent) has separate terms: Forge prompts, code and project files are de-identified and used by Bolt's partners to train open-source models, and you must accept that the first time you use Forge. The Model training toggle does not change Forge's terms. Forge sessions from the EEA, UK and Switzerland are excluded.
- Sources: Bolt docs: account settings, Model training · Bolt release notes (7 Oct 2026 entry) · Bolt docs: Forge data privacy (read 17 Oct 2026)
Our hands-on results for Bolt: Bolt review (tested).
Lovable
- Default: On for Free and Pro (may train). Business and Enterprise workspaces are excluded by default. Reported
- Opt out: Yes, free, Free and Pro plans. Account settings → Preferences → AI model training. Turn off "Use my Lovable content for model training". Direct link: lovable.dev/settings/account#privacy Reported
- What it covers: Prompts (with attached images and files), code, project files, hosted apps, configurations and generated output, from 9 Sep 2026. Not your app's end-user data, and not account or billing details. Reported
- Watch out for: Opting out works going forward only; it doesn't pull content out of datasets or models built before. The toggle is per person, so each collaborator on a shared project has to switch off their own.
- Sources: Lovable docs: manage training data and privacy · Lovable privacy policy (read 17 Oct 2026)
Our hands-on results for Lovable: Lovable review (tested).
Base44
- Default: On for every plan except Enterprise (may train). Includes Business. Reported
- Opt out: No setting. There is no opt-out to switch on. Only Enterprise workspaces are excluded, automatically. Reported
- What it covers: Your workspace data. On Enterprise, the exclusion also covers personal information people submit through your app's forms. Reported
- Watch out for: Base44's docs don't say whether, on non-Enterprise plans, the personal information your app's users type into forms can be used. They only say Enterprise excludes it. If your app collects personal data, ask Base44 before relying on it.
- Sources: Base44 docs: privacy and security, AI model training (read 17 Oct 2026)
Our hands-on results for Base44: Base44 review (tested).
v0
- Default: On (may train). v0 Enterprise content is excluded. Reported
- Opt out: Business ($100/user/month) and Enterprise, per v0's plan table. Vercel team settings → Data preferences (v0's FAQ links vercel.fyi/team-data-preferences). v0's plan table lists "Data Opt-out" as No on Free, Premium and Plus. Reported
- What it covers: Prompts and content you create in v0, which "may" be used as inputs to models and learning systems from third-party providers. Code and data from Vercel's hosting and deployment services are not used to train v0 if your team has opted out. Reported
- Watch out for: v0's FAQ says anyone who opted out in Vercel settings is excluded, while its plan table lists the opt-out only on Business and Enterprise. Check your own team's Data preferences page to see whether the switch is available to you. Deleting data later doesn't change models already trained on it.
- Sources: v0 docs: FAQs, training data · v0 docs: pricing (plan table) (read 17 Oct 2026)
Our hands-on results for v0: v0 review (tested).
Before you build something private
- Switch training off before you start. Lovable says opting out doesn't pull content from datasets or models built earlier, and v0 says deleting data doesn't update models already trained on it Reported.
- Keep secrets (API keys, passwords) out of prompts and in each tool's secrets or environment settings.
- On a shared project, each person controls their own setting on Lovable Reported. Ask collaborators to switch theirs off too.
- If your app collects other people's personal data, read the vendor's privacy policy and data processing terms, not just the toggle.
FAQ
Does Lovable train AI on my app?
Lovable says that from 9 Sep 2026 it may use Free and Pro plan content (prompts, code, project files, generated output) to train its models unless you opt out. Turn off "Use my Lovable content for model training" in Account settings, Preferences, AI model training. Business and Enterprise workspaces are excluded by default, and your app's end-user data is not used (Reported, Lovable docs, checked 17 Oct 2026).
How do I stop Bolt using my projects for training?
Click your avatar in Bolt's left sidebar, then Settings, General, and turn off Model training. It is on by default except for accounts in the EU, UK or Switzerland, and it covers content from 7 Oct 2026 onward. Bolt Forge has its own separate data-sharing terms that this switch does not change (Reported, Bolt docs, checked 17 Oct 2026).
Can I opt out of AI training on Base44?
Not on most plans. Base44's docs say workspace data on every plan except Enterprise, including Business, can be used to train AI models, and there is no opt-out setting. Enterprise is excluded automatically (Reported, Base44 docs, checked 17 Oct 2026).
Does v0 use my prompts for training?
v0's FAQ says it may use your prompts and content as inputs to models from third-party providers to improve its products. Enterprise content and teams that opted out in Vercel's Data preferences are excluded. v0's plan table lists the data opt-out on the Business ($100 per user a month) and Enterprise plans only (Reported, v0 docs, checked 17 Oct 2026).
Which AI app builder lets you opt out of training for free?
Of the four we test, Bolt and Lovable let any user switch training off for free in account settings. Base44 has no opt-out below Enterprise, and v0 lists the opt-out on its Business and Enterprise plans (Reported from each vendor's docs, checked 17 Oct 2026).
Did Bolt's free build weekend use my code for training?
We don't know, and Bolt's pages we read don't say. Bolt made GLM 5.3 Flash the only free model for its build weekend, which ended at 11:59pm PT on 18 Oct 2026. GLM 5.3 Flash is also one of Bolt Forge's models, and Forge shares de-identified prompts and code with partners to train open-source models under terms you accept on first use. If Bolt shows you data-sharing terms when you pick the model, read them: the Model training switch doesn't cover Forge (Reported and Inferred, checked 17 Oct 2026).
How to cite
VibeTierList, "Do Lovable, Bolt, Base44 and v0 train AI on your app? Defaults and how to opt out", from each vendor's docs, checked 17 Oct 2026. https://vibetierlist.com/research/ai-training-opt-out/