Reduce Time to First Byte (TTFB)

SkillDev tools

ttfb is a skill for auditing slow first responses on SSR pages, APIs, or cacheable HTML. It helps an agent measure why a webpage responds slowly by separating server processing time from network delays and caching issues, so fixes target the real cause.

Available today. Use it from your connected AI after setup.

Have an agent that can load and use skills.

Then ask your AI: use the Reduce Time to First Byte (TTFB) skill

What your AI can do with it

  • Audit slow first responses on SSR pages, APIs, or cacheable HTML
  • Distinguish origin compute time from network latency
  • Identify CDN cache misses as a cause of slow responses
  • Support diagnosis before proposing a fix

Getting started

  1. Have an agent that can load and use skills.
  2. Add the ttfb skill to the agent's available skills.
  3. Ask the agent to audit a slow SSR page, API endpoint, or cacheable HTML response.
  4. Review the breakdown of server processing time, network latency, and cache behavior before applying any fix.

What this skill tells your AI

The instructions your AI receives, as published by thedaviddias/front-end-checklist in skills/ttfb/SKILL.md and read by ahel’s review.

TTFB is the foundation of page performance; if the server is slow to respond, all subsequent loading stages are delayed.

Quick Reference

  • Optimize server-side logic and database queries to speed up response generation
  • Use a Content Delivery Network (CDN) to serve content closer to users
  • Implement effective caching strategies at the server and edge levels

Check

Review the page's TTFB and identify any bottlenecks in the server-side processing or network transmission.

Fix

Optimize the server's response time by improving database queries, caching responses, and using a CDN.

Explain

Explain how TTFB impacts the entire page load process and why it is a critical starting point for performance optimization.

Code Review

Review server-rendered routes, API handlers, cache configuration, and database access on the critical path. Flag uncached HTML, slow synchronous work before the first byte, repeated upstream fetches, or expensive queries that keep TTFB above roughly 800ms.


For full implementation details, code examples, and framework-specific guidance, see references/rule.md.

Rule page: https://frontendchecklist.io/en/rules/performance/ttfb

Signals

GitHub stars
74k
Forks
7k
Last commit
Aug 2026

Questions

When should this skill be used?
Use it when auditing slow first responses on SSR pages, APIs, or cacheable HTML, to find the cause before proposing a fix.
What does it measure?
It separates origin compute time from network latency and CDN cache misses, so the agent can tell which part of the response time is actually slow.
Does it fix performance problems?
No. It diagnoses the cause of slow first responses; fixes come after the diagnosis.
Advanced
Item type
skill
Key
ttfb
Source
github.com/thedaviddias/front-end-checklist