Supabase and Firebase alternative for AI-made games

This page is written by the KUMODeck team. It compares KUMODeck with Supabase and Firebase for a game or app you make with an AI such as ChatGPT, Claude or Claude Code, using facts from each service's official pages.

Supabase and Firebase are widely used general backends for apps, games among them. KUMODeck is a smaller, narrower backend for web games and apps that are made with an AI agent. They overlap on sign-in, data and hosting, and differ in who sets things up, which parts are built for games, and how you pay.

All three are reasonable choices. This page lists the facts so you can pick by what your game needs. The other services' facts come from their official pages, checked on 2026-10-29; their own pages are authoritative.

At a glance#

Sources for Supabase and Firebase, checked on 2026-10-29: Supabase pricing (free plan limits, pausing, Pro price), Supabase Realtime, Supabase Storage, Firebase pricing (Spark limits, Blaze), Firebase Realtime Database, Firebase Hosting. Prices and limits can change; their pages are authoritative.

Where KUMODeck is different#

Your AI does the setup, and you never handle a key. You connect your AI once by signing in in your browser. After that, "make it playable online" or "add cloud saves" turns the part on, writes the code and deploys a test version. Publishing to everyone waits for you to press Publish on a KUMODeck page. Keys for other services go into a small KUMODeck page, not the conversation, and a deploy whose files contain a secret key is stopped (Secrets in deployed files).

The parts are shaped for games. Players start as guests with nothing to fill in, and attach a sign-in later without losing anything (Authentication). Saves have a version per slot so two devices cannot overwrite each other (Cloud saves). Rooms come with codes, quick match and reconnects, and your AI asks one question about who plays before it picks the cheapest way to connect them (Play online together). Unity and Godot web exports run as they are (Unity games, Godot games).

There is no free tier. You pay at cost from the first request, and there is no plan to outgrow. A game that suddenly gets 100,000 plays in a month keeps running too, and the estimate on Pricing for that month is about $1.98 at list price. Because the balance is prepaid, the bill cannot grow past what you put in.

When Supabase fits better#

• You want a full Postgres database and to write SQL, use Postgres extensions or connect other tools to the same database.
• Your project is mostly an app with relational data, and the game is a small part of it.
• You want a free plan for a small project and are fine with it pausing after a week without use.
• You want something open source that you can also run yourself (Supabase on GitHub, self-hosting).

When Firebase fits better#

• You build native iOS or Android apps and want one backend with SDKs for them, alongside the web.
• You already use Google Cloud and want your backend in the same place.
• You want a free plan for a game with little traffic: Spark's daily allowances are enough for a small audience.
• You want Google's other app services that come with Firebase, such as Google Analytics and Cloud Messaging (Firebase products).

Adding saves and a high-score table to a game made with ChatGPT or Claude#

A game made in a ChatGPT or Claude conversation usually starts as one page with no backend. When players ask to keep their progress or see a high-score table, you can ask your AI in the same conversation where the game was made, and it adds the parts to the game it already put online (Publish a game you made with ChatGPT).

• Saves first, as guests. Every player starts as a guest with nothing to fill in, and their progress goes into a cloud save under a slot such as progress. Players sign in later to keep the same saves on another device (Add login and cloud saves).
• Keep scores out of saves. A player's own browser writes their saves, so a modified page can put anything in them. Saves are for what a player may change freely, such as settings and a solo game's progress. Scores and rankings belong in your own database, written only by your server code (Saves or your own database?).
• A leaderboard lives in your own database. Leaderboards are not a KUMODeck service: you build one in your own database and Functions. An AI agent working in a KUMODeck template, such as Claude Code or Codex, can use the leaderboard Skill that comes with the template to write the table, an endpoint for scores and the game's code. The code, the data and the rules are yours.
• Test, then publish. Each change goes to the test version first, and saves made while testing never show up in the published game. The public address waits for you to press Publish.

There is still no free tier: what these parts use is taken from your prepaid balance at cost, like the rest (Pricing).

You can use them together#

KUMODeck parts are optional and billed only when you use them. You can keep an existing Supabase or Firebase database and use KUMODeck only to host the game and run its rooms. A game hosted somewhere else can also use KUMODeck's sign-in, saves or rooms (Hosting & deploy explains web.allowedOrigins). Public keys meant for the browser, such as Supabase's publishable key or the apiKey in a Firebase config, are not stopped by KUMODeck's key check.

Try it#

Anyone can sign up (an invite code is optional: it adds credit to your balance). Start here connects your AI in a few minutes, and the questions and answers cover the common questions about cost and keys.