Braintrust
Evaluation, prompt playground, and observability for LLM apps in production.
Braintrust is an evaluation, prompt playground, and observability for LLM apps in production. Provides evaluation, prompt playground, and observability tools for LLM applications in a single platform.
About Braintrust
Braintrust is a platform providing evaluation, a prompt playground, and observability for LLM applications in production.
It combines evaluation, a prompt playground, and observability in one platform. It supports bring-your-own-key integration with multiple LLM providers, ships an open-source SDK for instrumenting LLM apps, and runs entirely in the browser without local installation.
It fits teams building and running LLM apps who need to test prompts, measure quality, and trace behavior in production. The free tier is subject to usage limits on evaluations and traces, and it is web-only with no dedicated IDE or desktop extension.
Sources: this listing
What it does well
- Provides evaluation, prompt playground, and observability tools for LLM applications in a single platform.
- Supports bring-your-own-key integration with multiple LLM providers.
- Offers an open-source SDK for instrumenting LLM applications.
- Runs entirely in the browser without requiring local installation.
Where it falls short
- Free tier is subject to usage limits on evaluations and traces.
- Available only as a web app, with no dedicated IDE or desktop extension.
Tagged
- Bring Your Own Key
- Web-based
- Enterprise Plan
- Free
- Freemium
- Open Source
Compared with similar things
Picked by shared tags inside the AI Web Apps.
- 01Freemium →Weaviate
Open-source vector database with hybrid search and generative module integrations.
- 02Freemium →OpenRouter
Unified API gateway for 200+ LLMs across providers with usage-based billing on a single account.
- 03Freemium →n8n
Open-source workflow automation with native LLM nodes — self-host on your own infrastructure.
- 04Freemium →Appsmith
Open-source low-code platform for internal apps, self-hostable and SOC2-certified.
- 05Freemium →Qdrant
Open-source, Rust-based vector database optimised for high-recall similarity search.
- 06Freemium →Hugging Face
Hub for ML models, datasets, and demos — the GitHub of open-source machine learning.
Related reading
- Where to Submit Your AI Tool
Submit your AI tool where people already search for one. Start with a niche AI tool directory (There's An AI For That, Futurepedia, and Vibedonalds for vibe-coded products), add a couple of general startup and SaaS directories, launch on one platform (Product Hunt or a smaller one like Uneed), and post in one community (a relevant subreddit or Show HN). Spread more directory submissions over the following weeks to get your first users.
Read guide → - How to Validate Your AI App Idea Before You Build It
The expensive mistake in the vibe-coding era isn't building the app — it's building the wrong one. You validate an AI app idea by talking to about eight people in your target market before you build, and listening for the single capability they all wish existed. That's your wedge. Higgsfield's founder did exactly that on the way to a ~$200M run-rate.
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Launch on Product Hunt by preparing for a few weeks: build genuine account activity, line up your assets and a supporter list, and ship at 12:01 AM Pacific (the daily reset) on a weekday. Reply to every comment all day, never ask for upvotes (say 'check it out'), and keep working the week after — that's where most of the lasting value is.
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Concepts you should know
- Eval
A reproducible test that measures how an LLM or LLM application performs on a specific task. Golden test sets, rubric grading, A/B comparisons. The closest thing to unit tests for prompts.
- LLM as judge
Using an LLM (often a stronger one than the one being tested) to grade outputs against a rubric. Replaces or supplements human grading for evals at scale. Accuracy of the judge is itself a metric you have to measure.
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</a>Frequently asked questions
- What is Braintrust?
- Braintrust is an evaluation, prompt playground, and observability for LLM apps in production.
- Is Braintrust free?
- Braintrust offers a free tier and paid plans with higher limits or premium features.
- What platforms does Braintrust support?
- Braintrust runs on web.
- What category does Braintrust belong to?
- Braintrust is in the AI Web Apps category — Web apps with AI baked in — built for everything from journaling to research. Submitter-shipped products live here.
- What are the downsides of Braintrust?
- Free tier is subject to usage limits on evaluations and traces. Available only as a web app, with no dedicated IDE or desktop extension.