AI & machine learning

21 tools

Braintrust

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Evaluate AI applications, compare prompts and manage test datasets.

FreemiumNo card

$0 Starter: $10 model credits/month, 1 GB processed data, 10k scores, 14-day retention and unlimited users/projects. No card.

Cerebras

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Run open AI models through an OpenAI-compatible API optimized for very fast inference.

Trial onlyNo card

Free inference tier with access to all Cerebras-powered models, lower rate limits and community support.

Cloudflare Workers AI

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Run serverless open-source AI models on Cloudflare's global GPU network.

FreemiumNo card

10,000 Neurons/day free across eligible models; usage above that is $0.011/1k Neurons on Workers Paid, and some heavy models require Paid.

Comet Opik

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Trace, evaluate and test LLM applications throughout development.

FreemiumNo cardOSS

Cloud Free: up to 10 members, 25k spans/month and 60-day retention; open-source self-hosting remains free.

fal.ai

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Call and deploy thousands of generative AI models through fast serverless APIs

Card

No free tier or trial for Model APIs; fal uses prepaid credits. New accounts start at 2 concurrent requests and scale to 40 as paid invoices accumulate.

Fireworks AI

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Serve open models with fast OpenAI-compatible inference and fine-tuning

Trial onlyNo card

New accounts get $1 in free credits. Without a payment method or active credits, the limit is 10 requests per minute; with credits, 6,000 per minute.

Freebuff

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A free, ad-supported coding agent available in the terminal, browser and cloud workspaces.

FreeNo card

Free with no subscription, API key or card; text ads fund usage and accounts receive 100 Freebucks/day, resetting at midnight Pacific.

Google AI Studio

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Prototype with Gemini models in a browser playground and generate API keys for development.

FreemiumNo card

AI Studio is free to use; selected Gemini API models include a free tier with model-specific rate limits.

Groq

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Build with fast hosted inference for open models through an OpenAI-compatible API.

FreemiumNo card

Free API plan with model-specific request and token limits; exact quotas are published in the Groq console docs.

Hugging Face

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Discover models and datasets, run demos and publish ML applications.

FreemiumNo card

Free Hub account with public/private repos, free CPU Basic or ZeroGPU Spaces and $0.10/month of Inference Providers credits.

Respan (formerly Keywords AI)

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Route 1,000+ AI models through one API with tracing, monitoring, budgets and automated evals

FreemiumNo card

Free entry plan is published at $0; Respan combines its multi-model gateway, tracing, monitoring and evaluation tools, with model inference billed separately.

Langfuse

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Open-source tracing, prompt management and evaluation for LLM products.

FreemiumNo cardOSS

Hobby: $0, 2 users, 50k usage units/month and 30-day data access; open-source self-hosting is also free.

Mistral AI

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Access Mistral's language, code, embedding and multimodal models through its developer API.

FreemiumNo card

$0 Free plan with $10/month in API credits for experimentation and lower limits; Labs models are free but experimental.

Modal

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Run Python workloads and AI infrastructure on serverless GPUs without paying for idle time

FreemiumCard

$0 Starter plan with $30 per month in free credits, 3 seats, 100 containers and 10 GPU concurrency. A payment method is required, and extra usage bills by time.

NotebookLM

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Research and reason across documents, websites, audio and other sources with grounded Gemini answers.

FreemiumNo card

100 notebooks with up to 50 sources each; since Sep 2026 AI interaction quotas are compute-based, refresh every 5 hours and are shown in-app.

NVIDIA NIM

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Prototype with hosted APIs for a rotating catalog of leading AI models and NVIDIA NIM microservices.

FreemiumNo card

Free hosted NIM API endpoints for prototyping through the NVIDIA Developer Program; available models and limits can change.

OpenRouter

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One API for many language models, including a rotating selection of free models.

FreemiumNo card

Free: 25+ free models, 4 free providers, 20 requests/min and 50/day; buying at least $10 in credits raises free-model daily use to 1,000.

Pollinations.AI

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Generate text, images, video, audio and embeddings through Pollinations APIs using Pollen credits

FreemiumNo card

API key required. Usage is metered in Pollen credits, earned through Quests or purchased; publishable keys are available for client apps.

Portkey

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An AI gateway and control plane with logging, routing and guardrails.

FreemiumNo card

Free Forever: 10k recorded logs/month, 3-day logs, 30-day metrics, gateway/fallbacks/retries, simple cache and guardrails.

Replicate

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Run thousands of community and official AI models through a simple API

Trial onlyNo card

Some models run free before billing; prediction endpoints allow 600 requests per minute and other endpoints 3,000. No fixed free-run quota; billing required once it ends.

Together AI

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Run and fine-tune open models through a fast OpenAI-compatible AI platform

Card

No free tier or trial; a minimum $5 prepaid credit purchase is required. Serverless inference uses dynamic per-model rate limits, and access pauses at a zero credit balance.

ABOUT US

Curated tools, honestly reviewed.

Every tool in this category has been manually reviewed. Pricing, free tier limits and card requirements are checked before listing.

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FAQ

Questions, answered.

Are these the best tools in this category?+

They're the ones we'd actually use. We prioritize tools with a clear use case, a working free tier, and honest pricing, not the most popular or most marketed.

How do I filter by free tools only?+

Use the pricing filter in the sidebar. Select Free or Freemium to narrow the list. Each card also shows whether a card is required.