The alternative to LLM as a judge for evals.

Composo gives you results you can actually trust, and for much less work. So you can accurately track performance changes over time & ship faster with confidence.

Working with leaders from companies like:

We get it, both manual & LLM-based evals don't work well.

You need precise, consistent & completely customizable metrics that you can 100% rely on. LLM-based evals can't do this.

We've built custom reward models that work better than an LLM as a judge.

Our models leverage a unique architecture and are custom-trained for evals so that they can be guaranteed upon to get the scores right.

build around...

Unique, research-backed approach

The only alternative to LLM as a judge, based on extensive R&D.

Testing in progress...

Ship faster, with confidence

Consistent, automated evals that enable you to quickly debug & improve the quality of LLM outputs.

Accurately track performance

Conduct precise, quantitative measurement of the impact of changes to prompts and models over time .

learning curve

Composo gives you evaluation results you can rely on.

Why companies choose Composo

5 mins to set up

Test out our evals API with just a few lines of code & simple, single sentence criteria.

Data security first

We're well-used to complex, sensitive use cases & working with enterprises in high-stakes domains such as finance, legal, healthcare & defence. Let us know your requirements.

Results you can trust

Our evals give you scores & explanations on any custom criteria, that are precise, deterministic & accurate.

Any application (inc. agents)

Built for all use cases including chatbots, copilots, code generation & unstructured data extraction.

We support RAG, agents, function calling & reasoning too.

Industry leading research

Custom generative reward models that are built to guarantee you get precise, deterministic evals you can trust.

Excels across benchmarks for real-world use cases.

Fully customisable

Type a single sentence to create any custom criteria.

Works for the most complex, subjective domains

Plus we can fine-tune for your use case if you need.

A smooth, yet
powerful workflow

all your apps

Our Blog

Our Team

seb

Sebastian Fox

CEO

Ex-McKinsey & QuantumBlack
Oxford University

Hao

Haoguo Wu

Founding Engineer

Ex-Tesla & Alibaba Cloud
Imperial College London

luke

Luke Markham

CTO

Ex-Graphcore ML Engineer
Oxford University

See how Composo compares to your current evals today

With evaluations built specifically for complex, highly specific domains, we make
it easy to deploy LLM applications with 100% confidence.