--- title: Monitor Performance with Calibre and Vercel description: Receive performance reports directly in your GitHub Pull Requests, following a Vercel deployment. url: /kb/guide/monitoring-performance-with-calibre-and-vercel canonical_url: "https://vercel.com/kb/guide/monitoring-performance-with-calibre-and-vercel" published: 2025-11-03 last_updated: 2026-06-15 authors: Lee Robinson related: - /docs/concepts/deployments/preview-deployments - /docs/deployments/git/vercel-for-github - /docs/concepts/deployments/git - /docs/concepts/deployments/environments install_vercel_plugin: npx plugins add vercel/vercel-plugin --- ## Related pages > **For AI agents:** Follow these links to understand how this page connects to the rest of the Vercel ecosystem. For the full cross-link map (inbound, outbound, prerequisites, and semantic neighbors), see the .graph.md link below. - [Deploying GitLab Projects with Vercel](https://vercel.com/docs/git/vercel-for-gitlab?from=related&source_path=%2Fkb%2Fguide%2Fmonitoring-performance-with-calibre-and-vercel&source_site=vercel-kb&relationship=related) — ​Vercel for GitLab automatically deploys your GitLab projects with Vercel, providing Preview Deployment URLs, and automa - [Deploying Bitbucket Projects with Vercel](https://vercel.com/docs/git/vercel-for-bitbucket?from=related&source_path=%2Fkb%2Fguide%2Fmonitoring-performance-with-calibre-and-vercel&source_site=vercel-kb&relationship=related) — ​Vercel for Bitbucket automatically deploys your Bitbucket projects with Vercel, providing Preview Deployment URLs, and - [Deploying GitHub Projects with Vercel](https://vercel.com/docs/git/vercel-for-github?from=related&source_path=%2Fkb%2Fguide%2Fmonitoring-performance-with-calibre-and-vercel&source_site=vercel-kb&relationship=related) — Vercel for GitHub automatically deploys your GitHub projects with Vercel, providing Preview Deployment URLs, and automat - [Managing Code Reviews](https://vercel.com/docs/agent/pr-review/usage?from=related&source_path=%2Fkb%2Fguide%2Fmonitoring-performance-with-calibre-and-vercel&source_site=vercel-kb&relationship=related) — Customize which repositories get reviewed and track your review metrics and spending. - [Deploying Git Repositories with Vercel](https://vercel.com/docs/git?from=related&source_path=%2Fkb%2Fguide%2Fmonitoring-performance-with-calibre-and-vercel&source_site=vercel-kb&relationship=related) — Vercel automatically deploys supported Git repositories on every branch push and when changes merge into the production - [Deploy Summary Integration](https://vercel.com/blog/deploy-summary?from=related&source_path=%2Fkb%2Fguide%2Fmonitoring-performance-with-calibre-and-vercel&source_site=vercel-kb&relationship=related) - [Monitor Frontend Performance with DebugBear and Vercel](https://vercel.com/kb/guide/monitor-frontend-performance-with-debugbear-and-vercel?from=related&source_path=%2Fkb%2Fguide%2Fmonitoring-performance-with-calibre-and-vercel&source_site=vercel-kb&relationship=related) — Automatically test each Vercel deployment and report performance changes to GitHub. - [How can I use CircleCI with Vercel?](https://vercel.com/kb/guide/how-can-i-use-circleci-with-vercel?from=related&source_path=%2Fkb%2Fguide%2Fmonitoring-performance-with-calibre-and-vercel&source_site=vercel-kb&relationship=related) — Learn how to use CircleCI to deploy to Vercel with custom CI/CD. - [How can I use Bitbucket Pipelines with Vercel?](https://vercel.com/kb/guide/how-can-i-use-bitbucket-pipelines-with-vercel?from=related&source_path=%2Fkb%2Fguide%2Fmonitoring-performance-with-calibre-and-vercel&source_site=vercel-kb&relationship=related) — Learn how to use Bitbucket Pipelines to deploy to Vercel including support for Bitbucket Data Center. - [Using Vercel Agent to review pull requests](https://vercel.com/kb/guide/vercel-agent-code-review?from=related&source_path=%2Fkb%2Fguide%2Fmonitoring-performance-with-calibre-and-vercel&source_site=vercel-kb&relationship=related) — Set up Vercel Agent Code Review to automatically review pull requests, apply validated fixes, request reviews with @verc - [How can I use GitLab Pipelines with Vercel?](https://vercel.com/kb/guide/how-can-i-use-gitlab-pipelines-with-vercel?from=related&source_path=%2Fkb%2Fguide%2Fmonitoring-performance-with-calibre-and-vercel&source_site=vercel-kb&relationship=related) — Learn how to use GitLab Pipelines to deploy to Vercel including support for self-managed GitLab. Full cross-link map for this page: [/kb/guide/monitoring-performance-with-calibre-and-vercel.graph.md](/kb/guide/monitoring-performance-with-calibre-and-vercel.graph.md?from=related&source_path=%2Fkb%2Fguide%2Fmonitoring-performance-with-calibre-and-vercel&source_site=vercel-kb&relationship=graph) [Calibre](https://calibreapp.com/) is a comprehensive monitoring platform that enables you to uncover and address performance issues. In this guide, you will learn how to receive performance [Pull Request Reviews](https://calibreapp.com/pull-request-reviews) directly in your pull requests following [Vercel Preview Deployments](https://vercel.com/docs/concepts/deployments/preview-deployments#). ## Step 1: Deploy with Vercel To deploy your project with the [Vercel for GitHub](https://vercel.com/docs/deployments/git/vercel-for-github), make sure your created project has been pushed to a Git repository. [Create a new project](https://vercel.com/new) into Vercel from GitHub. After your project has been imported, all subsequent pushes to branches will generate [Preview Deployments](https://vercel.com/docs/concepts/deployments/preview-deployments), and all changes made to the [Production Branch](https://vercel.com/docs/concepts/deployments/git#production-branch) (commonly `main`) will result in a [Production Deployment](https://vercel.com/docs/concepts/deployments/environments#production). > \*\*WARNING: \*\*While Vercel supports GitHub, Bitbucket, and GitLab, Calibre Pull Request Reviews currently work with Vercel and GitHub only. GitLab and Bitbucket are not supported. ## Step 2: Add Your Site to Calibre To receive performance metrics and reports, start by [creating a Calibre account](https://calibreapp.com/sign-up) and adding sites to monitor. You will be prompted to add a name, provide a URL, choose from 14 global test locations, and set a testing schedule. Calibre allows you to **check unlimited sites and pages**. Each site can be connected to a repository to receive Pull Request Reviews. If you’d like to learn more about how to successfully set up a performance monitoring system, read the Calibre [Getting Started](https://calibreapp.com/docs/get-started/guide) guide. ## Step 3: Connect Calibre to GitHub To enable Pull Request Reviews, from the Calibre Dashboard, go to **Site → Settings → Integrations** tab and click **Install** next to the GitHub logo. You will be redirected to GitHub to enable the integration for your organization. > \*\*Hint: \*\*Calibre requires access to commit statuses, deployments, checks, and pull requests. We strongly recommend only granting access to selected repositories you’re interested in tracking. ### Select a Comparison Branch After confirming the link between GitHub and Calibre, you will have to select a primary branch that will be the base for performance comparisons. This branch should be either deploying to production or a staging environment. In most cases, this might be the `master` branch. > \*\*Hint: \*\*For the most accurate results, **make sure you compare two very similar environments**. Some of the common differentiators producing unreliable results can be using a CDN on production, but not on Pull Request deployments, or the presence of ads or other third parties. When the selected branch is successfully deployed, Calibre [creates a deployment marker](https://calibreapp.com/docs/get-started/deploys) on your charts and takes a new snapshot of your site. That way, you always know how releases affect your performance metrics. ### Create a Pull Request Calibre will compare each Pull Request to the median of your site metrics since the last deploy. Each report highlights critical measurements (Lighthouse Performance Score, Time to Interactive and First Contentful Paint) overall and across [Test Profiles](https://calibreapp.com/test-profiles) to highlight top-level changes. You can analyze each page to see browser previews for specific Test Profiles and most significant changes, including any [Performance Budgets](https://calibreapp.com/performance-budgets) that have changed. Performance metrics highlighted in Pull Request Reviews can be customized in `/.calibre/config.yml`. Find out more about [configuration options](https://calibreapp.com/docs/get-started/pull-request-reviews#advanced-configuration).