This article guides you through enforcing web performance budgets using Sitespeed.io and Slack alerts while automating the entire process using CircleCI as the CI/CD tool.

Circle is a platform for developers and software teams to collaborate, share knowledge, and streamline their development workflows, offering tools and integrations for code review, continuous integration, and project management. Developers can learn about modern development practices, agile methodologies, and DevOps principles to improve collaboration, increase productivity, and deliver high-quality software efficiently.

CircleCI

Performance budgets prevent website regression by setting limits on metrics like load times and page weight. This guide demonstrates how to define performance budgets using time-based metrics (FCP, LCP, INP, CLS, TBT) and quantity-based metrics (page weight, HTTP requests, asset sizes). It walks through implementing these budgets with Sitespeed.io, automating tests in CircleCI pipelines, and configuring Slack notifications to alert teams when thresholds are exceeded. The tutorial includes practical setup steps for integrating these tools with a Next.js project deployed on Vercel.

Enforcing web performance budgets in CI/CD with Sitespeed.io and Slack

Implementing a performance budget with Sitespeed.io

Testing Slack alert on a failed Sitespeed.io test