Book a ConsultationNextvital — Next.js Performance Auditor
Nextvital calls Google PageSpeed Insights, pulls out every failure, and maps each one to the exact Next.js API that fixes it — next/image, next/font, dynamic imports, ISR, App Router patterns. No generic advice. Just ranked fixes with the code to ship them.
Every Next.js developer has opened Lighthouse, seen a score in the 50s, and stared at vague advice like 'serve images in next-gen formats.' That tells you nothing. Nextvital was built to close the gap between a Lighthouse report and an open code editor — it translates audit IDs directly into the Next.js patterns that fix them, shows before/after code, estimates savings, and tracks your progress as you ship each fix.
Screenshots
Features
Instant URL audit
Paste any public URL and Nextvital hits Google PageSpeed Insights v5 (Lighthouse 13), shapes the response, and returns a ranked list of failures within seconds. Results are cached for 24 hours so repeat audits are instant.
Next.js fix cards with code
Every audit failure maps to one of 38 Lighthouse audit IDs with a specific Next.js fix — next/image, next/font, dynamic imports, ISR, App Router patterns. Each card includes a collapsible before/after code example, a savings estimate, and a link to the official docs.
Progress dashboard
Every audit you run is saved automatically. The dashboard shows all past results in one place with a unified fix checklist ranked by impact — check off fixes as you ship them and watch your score climb.
Shareable permalink
Hit Copy share link on any results page to get a permanent /r/[id] URL. The shared page is fully server-rendered with correct OG metadata and JSON-LD schema, so it looks right when pasted into Slack or a Linear ticket.
BYOK AI action plan
Connect your own API key (Anthropic, Gemini, OpenRouter, or a local Ollama model) and turn the report into an interactive action plan. The AI sees only what's in the audit — it cannot invent scores or recommendations. Entirely optional, costs nothing unless you choose to use it.
Rate limiting & SSRF protection
Per-IP rate limits (5 live audits/hour), an in-flight lock to prevent duplicate concurrent requests, Zod validation, and a full SSRF blocklist covering private IPs, IPv6, and internal hostnames — so the audit endpoint is safe to expose publicly.
Frequently asked questions
Do I need a Google API key to run it?
Yes — a Google PageSpeed Insights API key is required. It's free from Google Cloud Console with a limit of 25,000 requests per day, which is more than enough for personal or small-team use.
What does 'BYOK AI' mean?
Bring Your Own Key. The AI layer is entirely opt-in and runs on your API key, not the server's. Supported providers: Anthropic, Google Gemini, OpenRouter, and local Ollama (no key needed, fully offline).
Can I use my Claude Pro or ChatGPT Plus subscription?
No — consumer subscriptions authenticate a browser session, not an API client. For a free alternative, grab a Google Gemini key from AI Studio in 30 seconds, or run a local model via Ollama at no cost.
Is it production-ready?
It ships with 402 Vitest tests, ESLint, TypeScript strict mode, and CI on GitHub Actions (Node 20 + 22). The pipeline includes Zod validation, SSRF protection, Redis-backed rate limiting, and a 24-hour cache.