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

Pros
ItemVotesUpvote
Works without login or API key1
Supports 50+ models out of the box1
Built-in support for variables and Jinja2 templating1
Instant response, no setup required1
Clean and distraction-free UI1
Cons
ItemVotesUpvote
No custom API key support (yet)1
Not ideal for running complex multi-turn chats1
Pros
ItemVotesUpvote
No pros yet, would you like to add one?
Cons
ItemVotesUpvote
No cons yet, would you like to add one?

Related Content & Alternatives

Related Content & Alternatives

Frequently Asked Questions

Related Content & Alternatives

  1. 0
    Image for Toolstash
    13.Toolstash

    Toolstash is a free tool tracking app for homeowners & hobbyists. Use AI to add all of your tools with the snap of a photo and let Toolstash take care of everything else! Keep track of what tools you have & where you put them, remember which neighbor borrowed what, and find out who nearby has that obscure tool you need for your upcoming weekend project! - Track: Keep track of your all the tools you have and where you have them (garage, workshop, office, etc. - AI Snap: Simply snap a photo to add a tool. We'll automatically identify the tool and model numbers for you. - DIY Chat: Get DIY help right away based on the tools you have! - Auto-Categorization: We'll automatically organize your tools for you. - Borrow/Lend: Keep track of which friend or neighbor has your tools!

  2. 0
    Image for Lisapet.ai
    50.Lisapet.ai

    Lisapet.ai is the next-level AI product development platform that empowers teams to prototype, test, and ship robust AI features 10x faster. Key Features - Best-in-class AI Playground: Swiftly test and iterate your prompts. Reduce the hassle of prompt prototyping. Our best-in-class AI playground makes the workflow faster, saving you time and effort in designing prompts. - Test-driven prompt engineering: Evalute and measure quality across large data sets. Build a collection of test cases to find the best prompt/model combination across different scenarios Benefits - Save Time: Cut down manual testing and free up your team to focus on shipping features. - Increase Confidence: Automate your testing to ensure reliable AI behavior before deployment. - Optimize Performance: Easily identify the best-performing prompts through side-by-side testing and real-time analytics. - Collaborate Seamlessly: Share progress with stakeholders and incorporate feedback directly within the platform. - Reduce Costs: Monitor token usage and optimize spending with detailed cost breakdowns. Use Case - Rapid Development of AI-Powered Features: Equip your product teams with tools to build, test, and launch AI-powered features without bottlenecks. - Scalable Prompt Engineering: Automate testing and validation to save time and reduce errors in prompt design. - Collaborative Testing: Enable cross-team collaboration by sharing reports and integrating feedback seamlessly.

  3. 0
    Image for RabbitHoles AI
    53.RabbitHoles AI

    RabbitHoles AI is an app to have AI conversations on an Infinite canvas. Each node on the canvas is a conversation. Multiple conversations can be connected to share context, along with adding other data sources like Pdf files, youtube videos, etc Key Features - Multiple Chats On Canvas: Have multiple connected chats with AI on the same canvas. - Unlimited Canvases: Create unlimited canvases - Latest Pro Models: Chat with all the popular LLM models from ChatGPT, Claude, Perplexity, Gemini, and Grok (xAI) - Bring Your Own Keys: Bring your own keys. Everything is stored locally - One-Time Purchase: Pay only once and use the product forever Benefits - No loss of context: As a side effect of branching chats, you control the length of the conversation; this prevents loss of context - Spatial Conversation: Learn/research faster on a whiteboard like canvas - Non-linear chats: Our brains don't think or learn linearly, so why should our chatbots be linear? - Multiple LLMs: Get different perspectives from multiple LLM models - Single Window: For every rabbit hole you go into, you stick to one infinite whiteboard that allows you to go deep into intellectual exploration Use Case Advanced AI Users can get what they want out of AI by having long explorative conversations with different AI models on an infinite canvas. There'll be less repetition, copy/pasting, and loss of context as you can: 1. Create branches of the conversations 2. Keep multiple conversations on a single canvas 3. Mix and match various chats to share context

  1. 0
    Image for StartKit.AI
    19.StartKit.AI

    StartKit.AI is a boilerplate designed to speed up the development of AI projects. It offers pre-built REST API routes for all common AI tasks: chat, images, long-form text, speech-to-text, text-to-speech, translations, and moderation. As well as more complex integrations, such as RAG, web-crawling, vector embeddings, and much more! It also comes with user management and API limit management features, along with fully detailed documentation covering all the provided code. Upon purchase, customers receive access to the complete StartKit.AI GitHub repository where they can download, customize, and receive updates on the full code base. 6 demo apps are included in the code base, providing examples on how to create your own ChatGPT clone, PDF analysis tool, blog-post creator, and more. The ideal starting off point for building your own app!

  2. 0
    Image for Narrow AI
    38.Narrow AI

    Introducing Narrow AI: Take the Engineer out of Prompt Engineering Narrow AI autonomously writes, monitors, and optimizes prompts for any model - so you can ship AI features 10x faster at a fraction of the cost. Maximize quality while minimizing costs - Reduce AI spend by 95% with cheaper models - Improve accuracy through Automated Prompt Optimization - Achieve faster responses with lower latency models Test new models in minutes, not weeks - Easily compare prompt performance across LLMs - Get cost and latency benchmarks for each model - Deploy on the optimal model for your use case Ship LLM features 10x faster - Automatically generate expert-level prompts - Adapt prompts to new models as they are released - Optimize prompts for quality, cost and speed Learn more at getnarrow.ai

  1. 1
    Image for Productivity Directory
    2.Productivity Directory

    Your ultimate tool finder, providing a curated list of productivity apps and tools designed to enhance your efficiency and streamline your workflow. Your ultimate tool finder, providing a curated list of productivity apps and tools designed to enhance your efficiency and streamline your workflow.

  2. 0
    Image for There's an AI
    3.There's an AI

    These days, AI directories are popping up all over the place. You’ve got huge lists—like that GitHub one —best-of-ai/ai-directories—and tons of sites trying to round up every AI tool under the sun. It’s a lot, right? Problem is, most of them are packed with meh tools. You dig through glitchy apps or overhyped stuff that doesn’t even work, and it’s a total time suck. Marketers like us? We don’t have time for that—we need tools that actually deliver. That’s where There’s an AI comes in. It’s not like those other messy directories. This one’s all about the good stuff—think of it like a stash of hidden gems, no junk allowed. You can navigate easily on different categories in it, jumping from content tools to ad optimizers without breaking a sweat. And the search? Oh, it’s clutch. You can type in whatever you want, and it pulls up only the best—no shitty tools clogging up your screen.

  3. 0
    Image for Startup Tools List
    4.Startup Tools List

    Discover, compare, and choose from a curated list of the best tools for startups. Equip your startup with the right tools to grow and scale fast. Discover, compare, and choose from a curated list of the best tools for startups. Equip your startup with the right tools to grow and scale fast. Discover, compare, and choose from a curated list of the best tools for startups. Equip your startup with the right tools to grow and scale fast.

  1. 1
    Image for Aitoolnet
    8.Aitoolnet

    Aitoolnet is a leading AI tool directory and search engine with over 10,000+ AI tools,updated daily. Find the latest AI tools for your work or creative projects.

  2. 0
    Image for Insanely Cool Tools
    13.Insanely Cool Tools

    This directory boasts 20,000 subscribers and if you get featured, you get a backlink. You'll also be featured in the newsletter. Insanely Cool Tools is free to use but you may need to pay if you want to skip the queue.

  3. 0
    Image for Shnoco
    18.Shnoco

    Shnoco offers a directory of no-code tools. If your product allows users to build and develop software and products without code, it's the place to get listed. They get 27,500+ visitors a month, mostly bootstrapped entrepreneurs, solo founders and no-code enthusiasts.

  4. 0
    Image for AI Tools
    22.AI Tools

    AI Tools is a directory of all AI-driven products. It features AI assitants, SEO AIs, eCommerce AIs, programming AIs and many more. It's easy to submit your tools and it's free to use.

  5. 0
    Image for Indietool
    26.Indietool

    Indietool is a directory for apps and tools built by indie hackers and solopreneurs. You receive a dofollow link to help you with SEO.

  6. 0
    Image for Static Page Tools
    30.Static Page Tools

    Explore our curated directory of static site generators, from Next.js to Hugo, and find the best tools for adding search, comments, and other features to your static website. Start building a fast, secure, and optimized website now.

  7. 0
    Image for AI Tools Explorer
    34.AI Tools Explorer

    AI Tools Explorer is a 100% human-curated and edited directory of top-quality, SFW AI tools and apps, organized by category and updated daily with helpful AI guides and resources.

  8. 0
    Image for Mactools
    37.Mactools

    An Exclusive list of the best Mac apps and tools. You can submit your Mac app or tool to get exposure to an engaged audience of Mac enthusiasts, developers, and professionals seeking new apps and tools to explore.

  9. 0
    Image for Top Writer Tools
    38.Top Writer Tools

    A directory of writer tools, including AI-generators, AI-detectors, and plagiarism scoring systems. Our curated collection highlights the most popular writing tools, ranked according to user satisfaction and effectiveness. We've categorized these tools into four main segments: AI Writing Assistants & Generators, Plagiarism Checkers & AI Detectors, Copywriting Tools & Content Generators, and Book Writing & Creative Writing Tools. Each section is designed to help you find the right stack for your specific writing and copywriting needs.

  10. 0
    Image for Top SEO Tools
    39.Top SEO Tools

    Discover the right SEO stack for your project by exploring our curated list of tools. From AI-driven optimizers to widely-used research platforms, we've got everything to help you succeed in the competitive digital landscape.

feedback