# Composal vs Lost Pixel

Lost Pixel asks whether a captured UI differs from its baseline and offers a visual-test workflow.

## Composal

Composal sends AI browser agents to use your running web app and check the outcomes you care about. Define journeys as plain-English Scenarios, map existing flows with Discovery, or explore for bugs with Deep Scan. Runs keep recordings and reproduction steps so your team or coding agent can investigate a Finding.

[Verify documentation](https://composal.com/docs/verify)

## Lost Pixel

Open-source and hosted visual regression testing

Lost Pixel provides visual regression testing for Storybook, Ladle, and web applications, with an open-source runner and a hosted platform. Teams capture screenshots, compare them against baselines, and review changes through their development workflow.

## What each tool does

| Workflow | Composal | Lost Pixel |
| --- | --- | --- |
| [Run browser journeys](https://composal.com/product/scenarios) | ✓ Yes: Run saved browser Scenarios and return recordings and reproducible Findings. | – With setup: Captures or compares rendered pages through a configured test or visual workflow; confirm the supported runner. |
| [Map application workflows](https://composal.com/product/discovery) | ✓ Yes: Discovery maps key application areas and user journeys. | – Not confirmed: Check whether this product includes this workflow in your intended plan and setup. |
| [Explore for unexpected issues](https://composal.com/product/deep-scan) | ✓ Yes: Deep Scan explores the running application and reports reproducible issues. | – Not confirmed: Check whether this product includes this workflow in your intended plan and setup. |
| [Describe checks in plain English](https://composal.com/product/scenarios) | ✓ Yes: Author Scenarios around the intended user outcome, then review the steps and expected results. | – Not confirmed: Check whether this product includes this workflow in your intended plan and setup. |
| [Run or inspect from a terminal](https://composal.com/product/cli) | ✓ Yes: Use the CLI to start and inspect verification runs and their Findings. | – Not confirmed: Check whether this product includes this workflow in your intended plan and setup. |
| Visual regression baselines | × No: Use a dedicated tool for this specialist workflow alongside Composal’s browser verification. | ✓ Yes: Lost Pixel provides visual regression testing for Storybook, Ladle, and web applications, with an open-source runner and a hosted platform. Teams capture screenshots, compare them against baselines, and review changes through their development workflow. |

With setup means you supply code or configuration. Not confirmed means support for this workflow needs checking with the vendor.

## Where each fits

Choose Lost Pixel when screenshot comparison, Storybook coverage, or an open-source visual-testing foundation fits your frontend process.

## Try this evaluation

Select two states: a component documented in Storybook and an application journey that submits it in context. Make one styling change and one interaction change.

### Coverage

Which user outcomes must this release prove, and which specialist checks must stay in your existing stack?

### Setup

Who prepares accounts, test data, permissions and access to the deployment being tested?

### Evidence

Can the engineer reproduce a reported failure from the recording and steps, without asking the tester to investigate again?

### Ownership

Who updates the checks when the product changes, and can the team review what a passing result actually proves?

## Related comparisons

- [Composal vs Argos](https://composal.com/compare/composal-vs-argos.md)
- [Composal vs BackstopJS](https://composal.com/compare/composal-vs-backstopjs.md)
- [Composal vs reg-suit](https://composal.com/compare/composal-vs-reg-suit.md)

[All comparisons](https://composal.com/compare.md)