benchmark

Measures web performance metrics and compares them against a stored baseline.

Updated Apr 1, 2026

Search Tags:#performance #benchmark #web-vitals #baselines #lcp #ttfb

Ready to run

npx skills add https://github.com/whd4/gstack --skill benchmark-whd4

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: benchmark
Source: https://github.com/whd4/gstack/tree/main/benchmark
Command: npx skills add https://github.com/whd4/gstack --skill benchmark-whd4

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Measures web performance metrics across PRs to detect regressions early.

Core Features & Use Cases

Baseline captures and stores performance baselines for pages.
Per-page metrics: TTFB, FCP, LCP, DOM timings, and resource counts.
Trend analysis and diff mode to surface regressions over time.
Automated reporting to .gstack/benchmark-reports and a machine-readable baseline JSON.

Quick Start

Run /benchmark https://example.com to perform a full performance audit against the current baseline.

Frequently Asked Questions about benchmark

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I measure web performance metrics like LCP and TTFB against a baseline?▼

You can measure web performance metrics by running a benchmark audit against a stored baseline. The tool collects TTFB, FCP, LCP, and DOM timings, then compares current results to the baseline JSON to detect regressions.

What is the best way to detect web performance regressions across pull requests?▼

The best way to detect web performance regressions across PRs is to capture a performance baseline and run diff or trend analysis. This compares current page metrics against stored baselines to surface degradations early.

Can I automate collecting Core Web Vitals and bundle sizes for reporting?▼

Yes, you can automate collecting Core Web Vitals and bundle sizes. The tool outputs a structured JSON file for automation alongside a human-readable report, capturing total requests and resource counts.

How does trend analysis work when comparing web vitals over time?▼

Trend analysis works by evaluating in-page timing data via JavaScript and comparing it against an existing baseline. It handles quick, diff, and trend modes to surface performance changes over time.

Do I need a specific browser daemon to capture DOM timings and resource counts?▼

Yes, you need the browse daemon’s perf command to drive pages and capture DOM timings. The tool relies on this daemon to collect comprehensive web-performance metrics for analysis.