Braintrust
↗Evaluate AI applications, compare prompts and manage test datasets.
$0 Starter: $10 model credits/month, 1 GB processed data, 10k scores, 14-day retention and unlimited users/projects. No card.
21 tools
Evaluate AI applications, compare prompts and manage test datasets.
$0 Starter: $10 model credits/month, 1 GB processed data, 10k scores, 14-day retention and unlimited users/projects. No card.
Run open AI models through an OpenAI-compatible API optimized for very fast inference.
Free inference tier with access to all Cerebras-powered models, lower rate limits and community support.
Run serverless open-source AI models on Cloudflare's global GPU network.
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.
Trace, evaluate and test LLM applications throughout development.
Cloud Free: up to 10 members, 25k spans/month and 60-day retention; open-source self-hosting remains free.
Call and deploy thousands of generative AI models through fast serverless APIs
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.
Serve open models with fast OpenAI-compatible inference and fine-tuning
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.
A free, ad-supported coding agent available in the terminal, browser and cloud workspaces.
Free with no subscription, API key or card; text ads fund usage and accounts receive 100 Freebucks/day, resetting at midnight Pacific.
Prototype with Gemini models in a browser playground and generate API keys for development.
AI Studio is free to use; selected Gemini API models include a free tier with model-specific rate limits.
Build with fast hosted inference for open models through an OpenAI-compatible API.
Free API plan with model-specific request and token limits; exact quotas are published in the Groq console docs.
Discover models and datasets, run demos and publish ML applications.
Free Hub account with public/private repos, free CPU Basic or ZeroGPU Spaces and $0.10/month of Inference Providers credits.
Route 1,000+ AI models through one API with tracing, monitoring, budgets and automated evals
Free entry plan is published at $0; Respan combines its multi-model gateway, tracing, monitoring and evaluation tools, with model inference billed separately.
Open-source tracing, prompt management and evaluation for LLM products.
Hobby: $0, 2 users, 50k usage units/month and 30-day data access; open-source self-hosting is also free.
Access Mistral's language, code, embedding and multimodal models through its developer API.
$0 Free plan with $10/month in API credits for experimentation and lower limits; Labs models are free but experimental.
Run Python workloads and AI infrastructure on serverless GPUs without paying for idle time
$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.
Research and reason across documents, websites, audio and other sources with grounded Gemini answers.
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.
Prototype with hosted APIs for a rotating catalog of leading AI models and NVIDIA NIM microservices.
Free hosted NIM API endpoints for prototyping through the NVIDIA Developer Program; available models and limits can change.
One API for many language models, including a rotating selection of free models.
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.
Generate text, images, video, audio and embeddings through Pollinations APIs using Pollen credits
API key required. Usage is metered in Pollen credits, earned through Quests or purchased; publishable keys are available for client apps.
An AI gateway and control plane with logging, routing and guardrails.
Free Forever: 10k recorded logs/month, 3-day logs, 30-day metrics, gateway/fallbacks/retries, simple cache and guardrails.
Run thousands of community and official AI models through a simple API
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.
Run and fine-tune open models through a fast OpenAI-compatible AI platform
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
Every tool in this category has been manually reviewed. Pricing, free tier limits and card requirements are checked before listing.
FAQ
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.
Use the pricing filter in the sidebar. Select Free or Freemium to narrow the list. Each card also shows whether a card is required.