Pre-Launch Performance Audit
Run a full Lighthouse audit before launching your site to catch performance, accessibility, and SEO issues.
Measure Time to Interactive
Measure how long it takes for your page to become fully interactive and identify what delays user input.
ToolTime to Interactive (TTI) measures how long it takes before a user can reliably interact with your page -- clicking buttons, filling forms, scrolling smoothly. A page might look loaded while JavaScript is still executing in the background, creating a frustrating experience where clicks and taps are ignored or delayed.
Lighthouse measures TTI along with related metrics like Total Blocking Time and First Input Delay. Together, these reveal how much JavaScript execution is blocking the main thread and preventing user interaction. The most common culprits are large JavaScript bundles, synchronous third-party scripts, and expensive DOM operations.
Optimizing TTI is especially critical for e-commerce checkout flows, form-heavy pages, and any interactive feature where delayed response directly impacts conversions. A page that looks ready but does not respond to input is worse than a page that is honestly still loading.
Agent Guides
Claude
- Connect ToolRouter: claude mcp add toolrouter -- npx -y toolrouter-mcp
- Ask Claude: "Run a Lighthouse audit on mysite.com/checkout and focus on Time to Interactive"
- Claude reports TTI, Total Blocking Time, and main-thread blocking sources
ChatGPT
- Configure ToolRouter in ChatGPT
- Ask: "Measure Time to Interactive on mysite.com/app and explain the results"
- ChatGPT breaks down what is blocking interactivity in plain language
Copilot
- Add ToolRouter to Copilot MCP config
- Ask: "Measure Time to Interactive on mysite.com/page"
- Review TTI and blocking time diagnostics
OpenClaw
- Connect ToolRouter: openclaw mcp add toolrouter -- npx -y toolrouter-mcp
- Ask: "Measure Time to Interactive on mysite.com/page"
- OpenClaw reports TTI and identifies blocking resources
Related Use Cases
Diagnose Slow Page Load Times
Identify the root causes of slow page loads using Lighthouse performance diagnostics and metrics.
Check Accessibility Compliance
Audit your pages for WCAG accessibility issues using Lighthouse to ensure your site works for all users.
Identify Render-Blocking Resources
Find CSS and JavaScript files that block page rendering and delay the first paint for users.