Langfa.st vs. Tools.so
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.
Tools.so
Tools.so is a directory of high quality tools from all over the internet. Some examples include Notion, Prisma, Mixpanel, Render and Betalist.
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 |
|---|---|---|
| No pros yet, would you like to add one? | ||
| 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, supporting over 50 large language models without the need for login or API keys. It offers features like variable support and Jinja2 templating, making it ideal for AI teams and prompt engineers. In contrast, Tools.so is a directory of various high-quality tools but does not focus on AI prompt testing. Therefore, for users specifically looking to experiment with AI prompts, Langfa.st is the better choice.
Yes, Langfa.st provides a range of features tailored for AI experimentation, including support for multiple language models, built-in variable handling, and a distraction-free UI. Tools.so, while it offers a collection of tools, does not provide specific features for AI prompt testing or experimentation. Thus, Langfa.st is more feature-rich for users focused on AI.
Langfa.st is designed for ease of use, allowing users to start testing AI prompts immediately without any setup or login requirements. Its clean interface and instant responses enhance the user experience. Tools.so, being a directory, may require users to navigate through various tools to find what they need, making Langfa.st the easier option for direct AI prompt testing.
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.
Tools.so is a directory of high-quality tools from all over the internet. The platform features a variety of tools including Notion, Prisma, Mixpanel, Render, and Betalist. It serves as a comprehensive resource for discovering useful software and services.
Tools.so includes a wide range of tools from different categories such as project management, analytics, development, and marketing. Examples of tools listed on the site are Notion for project management, Prisma for database management, Mixpanel for analytics, Render for cloud hosting, and Betalist for startup discovery.
The main features of Tools.so include its curated directory of high-quality tools, user reviews, ratings, and detailed descriptions of each tool. The platform is designed to help users easily discover and evaluate tools that can enhance their productivity or meet specific needs.
