---
title: "07.09.2025: Baseline for experiment comparisons"
description: Available in Phoenix 11.4+
---

<Update label="07.09.2025">

## Baseline for Experiment Comparisons

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You can now set a **baseline run** when comparing multiple experiments. This is especially useful when one run represents a known-good output (e.g. a previous model version or a CI-approved run), and you want to evaluate changes relative to it.

For example, in an evaluation like `accuracy`, you can easily see where the value flipped from `correct → incorrect` or `incorrect → correct` between your baseline and the current comparison - helping you quickly spot regressions or improvements.

This feature makes it easier to isolate the impact of changes like a new prompt, model, or dataset.

<Card title="feat(experiments): add baseline to compare experiments page by axiomofjoy · Pull Request #8461 · Arize-ai/phoenix" icon="github" href="https://github.com/Arize-ai/phoenix/pull/8461" horizontal>
  GitHub
</Card>
</Update>