---
title: How to determine which Vercel Deployment introduced an issue?
description: Process to quickly determine when a deployment issue was introduced using the Vercel CLI
url: "https://vercel.com/kb/guide/how-to-determine-which-vercel-deployment-introduced-an-issue"
published: 2025-11-03
last_updated: 2025-11-10
authors: Holden Altaffer
install_vercel_plugin: npx plugins add vercel/vercel-plugin
---

With Vercel Preview Deployments and [bisecting](https://vercel.com/docs/cli/bisect), you can quickly and efficiently determine which commit introduced a regression in your application, and then [instantly rollback](https://vercel.com/docs/concepts/deployments/instant-rollback).

[Watch a video tutorial](https://www.youtube.com/watch?v=6CTdji6s1GQ) or learn more in the following guide.

```bash
vercel bisect
```

## Use Vercel Bisect to find first broken deployment

Vercel Bisect is a command, inspired by the [git bisect](https://git-scm.com/docs/git-bisect) command, that helps identify the first Deployment an issue was introduced by traversing a range of preview deployments, marking them as either "good" or "bad". This tool was released in version 24 of the CLI.

To start your debugging session, run `vc bisect` in the terminal and you will be given an interactive prompt to help find where the bad commit was introduced. Start with a deployment URL where the bug occurs. Next, specify a deployment URL where the bug does _not_ occur. Lastly, specify a subpath to narrow down by page, such as `/login` or `/`.

Vercel Bisect will retrieve a list of deployments for you to review, starting in the middle of the list, utilizing a [Binary Search](https://en.wikipedia.org/wiki/Binary_search_algorithm). At each step, you’ll indicate if the deployment is “good” or “bad” to quickly narrow down to the root cause The number of steps left will be visible. After the full list of deployments has been traversed, the first bad deployment will be shown with the date, commit with message, and URL to inspect the deployment on the dashboard.

You can then [instantly rollback to a previous deployment](https://vercel.com/docs/concepts/deployments/instant-rollback) with Vercel.

## More Vercel CLI guides

- [How can I run end-to-end tests after my Vercel Preview Deployment?](/kb/guide/how-can-i-run-end-to-end-tests-after-my-vercel-preview-deployment): Learn how to use the Vercel CLI in combination with your CI/CD provider to run end-to-end tests for every code change.
- [How to Deploy a Brunch App with Vercel](/kb/guide/deploying-brunch-with-vercel): Create a Brunch app and deploy it live with Vercel.
- [How can I use Bitbucket Pipelines with Vercel?](/kb/guide/how-can-i-use-bitbucket-pipelines-with-vercel): Learn how to use Bitbucket Pipelines to deploy to Vercel including support for Bitbucket Data Center.