Langfa.st vs. Firebase
Langfa.st
Langfa.st is a fast and minimal playground for testing and refining AI prompts. It supports over 50 large language models, including OpenAI, Anthropic, Mistral, Cohere, Google, and others — all available instantly without setup. You can insert variables, use Jinja2 templating, and compare outputs across models. There’s no need to sign up or bring your own API keys — it works out of the box. Langfa.st was built to eliminate the friction of existing tools: complicated UIs, required credentials, or overpriced subscriptions. It gives AI teams and prompt engineers a clean, disposable space to experiment, debug, and iterate — all in one tab. Free to use. You only pay if you need more volume or power features.
Firebase
Google's Firebase is an entire app development platform that's packed with features.It comes with storage, cloud functions, monitoring and, of course, user authentication. The free tier comes with 50,000 MAUs. Beyond that pricing start at $0.0055/MAU and goes down to as low as $0.0025/MAU as you scale to millions of users. Firebase authentication supports email and password auth, phone auth, magic links, two-factor authentication and social identity providers - mainly Google, Google Play Games, Facebook, Apple, Microsoft, Twitter, GitHub and OAuth access tokens.
Reviews
Reviews
| Item | Votes | Upvote |
|---|---|---|
| Works without login or API key | 1 | |
| Supports 50+ models out of the box | 1 | |
| Built-in support for variables and Jinja2 templating | 1 | |
| Instant response, no setup required | 1 | |
| Clean and distraction-free UI | 1 |
| Item | Votes | Upvote |
|---|---|---|
| No custom API key support (yet) | 1 | |
| Not ideal for running complex multi-turn chats | 1 |
| Item | Votes | Upvote |
|---|---|---|
| Easy to use | 1 | |
| Low price per monthly active user | 1 | |
| Generous free tier | 1 | |
| Easy SMS authentication | 1 |
| Item | Votes | Upvote |
|---|---|---|
| No cons yet, would you like to add one? | ||
Frequently Asked Questions
Langfa.st is specifically designed for testing and refining AI prompts, offering instant access to over 50 large language models without the need for login or API keys. It provides a clean and distraction-free UI, making it ideal for prompt engineers. In contrast, Firebase is a comprehensive app development platform that includes user authentication and other features, but it is not tailored for AI prompt testing. Therefore, if your primary focus is on AI prompt experimentation, Langfa.st would be the better choice.
Firebase offers a robust user authentication system that supports various methods, including email/password, phone authentication, and social identity providers. This makes it suitable for app development where user management is essential. On the other hand, Langfa.st does not focus on user authentication and lacks custom API key support, making it less suitable for applications requiring user management. If user authentication is a priority, Firebase is the clear winner.
Langfa.st is free to use for basic features, with costs only incurred for higher volume or power features, making it very cost-effective for AI prompt testing. Firebase has a free tier but charges based on monthly active users beyond that, which can add up depending on the scale of your application. For pure AI prompt testing without the need for extensive user management, Langfa.st is likely the more cost-effective option.
Langfa.st is not ideal for running complex multi-turn chats, as it is primarily focused on prompt testing and refinement. Firebase, while not specifically designed for chat applications, provides a more comprehensive backend solution that can support complex interactions through its cloud functions and real-time database features. Therefore, for applications requiring complex multi-turn chat capabilities, Firebase would be the better choice.
Langfa.st is a fast and minimal playground for testing and refining AI prompts. It supports over 50 large language models, including OpenAI, Anthropic, Mistral, Cohere, Google, and others — all available instantly without setup. Users can insert variables, use Jinja2 templating, and compare outputs across models without needing to sign up or provide API keys.
Pros of Langfa.st include: it works without login or API key, supports over 50 models out of the box, has built-in support for variables and Jinja2 templating, provides instant responses with no setup required, and features a clean and distraction-free user interface.
Cons of Langfa.st include the lack of custom API key support at this time and it may not be ideal for running complex multi-turn chats.
Langfa.st is particularly beneficial for AI teams and prompt engineers who need a clean, disposable space to experiment, debug, and iterate on AI prompts without the friction of complicated UIs or required credentials.
Yes, Langfa.st is free to use. Users only pay if they need more volume or access to power features.
Firebase is Google's app development platform that offers a comprehensive suite of features, including storage, cloud functions, monitoring, and user authentication. It supports multiple authentication methods such as email and password, phone authentication, magic links, two-factor authentication, and social identity providers like Google, Facebook, Apple, Microsoft, Twitter, GitHub, and OAuth access tokens.
Pros of Firebase include its ease of use, low price per monthly active user, a generous free tier, and easy SMS authentication. Currently, there are no user-generated cons for Firebase.
The free tier for Firebase includes 50,000 monthly active users (MAUs). Beyond that, pricing starts at $0.0055 per MAU and can go as low as $0.0025 per MAU as you scale to millions of users.
Firebase supports multiple authentication methods, including email and password, phone authentication, magic links, two-factor authentication, and social identity providers such as Google, Google Play Games, Facebook, Apple, Microsoft, Twitter, GitHub, and OAuth access tokens.
