Kubbler vs Bolt: from prototype to product.

Bolt spins up a full environment in the browser and generates the whole application. Kubbler composes the product layer on top of a foundation written by engineers. The first is unbeatable for trying things; here is what the second changes when it is time to ship.

capabilities written by engineers, never generated
22capabilities written by engineers, never generated
tokens spent on the size of your project
0tokens spent on the size of your project
monthly subscription, hosting included
1monthly subscription, hosting included
Project templates
In one sentence

Which of the two, for you.

Go with

Bolt

You are prototyping, and you want the shortest path between an idea and something that runs. Bolt opens a full environment in the browser in seconds, imports a Figma file or a repository, accepts any library, and lets you throw the result away without regret. For exploring, we do not claim to do better.

Go with

Kubbler

The prototype has to become the product, and somebody is going to pay inside it. Accounts, payments, emails, backups and deployment are not there to be generated: they are written, tested and operated by engineers, identical for every project. You keep the speed of the prompt and you lose the wall at shipping time.

Line by line, no corners rounded off.

Every line about the other product comes from its own public documentation. The two lines where it beats us are in the table, not buried further down.

CriterionBoltKubbler
What the AI writes
The foundations: accounts, payments, security, data
A database is provided on every plan. Accounts, payments and security are generated inside the project.
Written by engineers, once, identical for every project. Never generated.
What the AI re-reads on every message
The project's file system is synced to the AI: the larger the project, the more tokens each message costs.
Your description of the product. The platform is not in the generation loop.
What ships with it
Accounts and authentication
Generated inside the project, then reviewed by you.
Shipped, screens included: sign-up, forgotten password, two-factor authentication, roles.
Payments
Generated and wired inside the project.
Stripe on your own account: one-off, subscriptions, failed charges, invoices.
Transactional emails
Wired to a third-party service from inside the project.
Written, translated and sent by the platform: confirmation, invoice, follow-up, reset.
Interface
Generated in a full environment running in the browser, Figma and GitHub import included.
81 blocks already designed, composed by the AI then adjusted in four visual editors.
Data and hosting
Database
Databases provided, with no announced limit on the number across plans.
A dedicated database per project, isolated from the others, with automatic backups.
Hosting and custom domain
Hosting included. Custom domain from the paid plan, Bolt branding on the free plan.
A dedicated container in Paris at Scaleway. Domain, HTTPS certificate and backups included.
Reversibility
Exporting the product code
Download the project as an archive, plus GitHub integration.
GitHub export from the editor: conventional JavaScript on Next.js.
Your team taking over the foundations
A standard application: you open it in your editor and host it wherever you want.
The platform stays operated by us. That is what lets us fix it for everyone, and it is the trade-off to accept.
How much you can build
Whatever the model can write, with any npm library.
Whatever 22 capabilities and 81 blocks cover. That is wide, it is not infinite.
Economics
Billing model
Tokens, whose consumption follows the size of the project, with a daily cap on the free plan.
A monthly subscription, hosting included, that does not move with the size of the project.
Taking your customers' money
Straight to you, through the payment integration you set up.
Your own Stripe account. No commission taken by us.

Comparison checked on 10 September 2026 against the vendor's public documentation. These products move fast: if a line is wrong, write to us and we will fix it.See the source

The three differences that matter.

Three gaps that are not a matter of settings, but of what each product is trying to do.

01

The foundations never go through the model

Bolt generates the whole application, accounts and payments included, in an environment that lives in your browser. That is exactly what makes it so fast to try. Here that layer is never generated: it is written once, reviewed, run in production, and shared by every project.

Accounts, two-factor authentication, roles and abuse quotas: the same code for everyone.

Stripe payments: one-off, subscriptions, failed charges and invoices, on your own account.

A fix in the platform reaches every customer the same day, with nobody re-prompting anything.

Customer accounts
02

The cost of a message should not grow with the project

Bolt says it themselves: tokens go first to syncing the project's file system to the model, so the larger the project, the more each message costs. That is the logical consequence of generating everything. Here the foundation is not in the loop: there is nothing to re-sync as the application grows.

A monthly subscription: hosting, certificate and backups included.

No commission on what you take in, payments run through your own Stripe account.

The price of a change depends neither on the number of files nor on the age of the project.

Dashboard
03

What you take with you, and what you leave

On this point Bolt is ahead, and it should be said: you download the project as an archive, open it in your editor, host it wherever you want, and nothing holds you back. On our side the code of your product exports to GitHub, but the foundation stays operated by us.

Your product exports at any time: conventional JavaScript any developer can read.

The platform itself stays with us. That is the price of having it run and fixed for every project at once.

Worth noting on their side: on the free plan, published sites carry Bolt branding, and custom domains start at the paid plan.

Block editor

The questions we get asked.

Precise answers, including the ones that do not favour us.

Prototype wherever you like. Ship here.

Free during the beta, no card required. Take the idea you have just tried, describe it, and see what is actually left to do to put it online.