Time to First Byte (TTFB)
Time to First Byte (TTFB) measures the time between a client sending an HTTP request and receiving the first byte of the response. It includes DNS lookup, connection setup, TLS negotiation, network travel, and server processing time, making it a core indicator of backend and network responsiveness.
Technical Architecture & Deep-Dive
A high TTFB delays everything that follows: the browser cannot render content and a mobile app cannot display data until the first bytes arrive. Common causes include distant origin servers, slow database queries, cold starts, and sequential upstream API calls.
Serving responses from an edge location close to the user eliminates long network paths, and edge caching avoids origin processing entirely on cache hits. Parallel upstream fan-out further shortens TTFB for aggregated endpoints.
Key Architectural Benefits
Implement Time to First Byte (TTFB) at the Edge
Deploy lightweight API aggregation, edge caching, and secret injection in minutes without Docker containers or complex servers.
Frequently Asked Questions
Q:What is a good TTFB?
Google recommends a TTFB of 800 milliseconds or less for page loads. For API responses served from the edge, well under 100 milliseconds is achievable.
Related Architecture Concepts
Sub-10ms Edge Latency describes API response times that complete in under 10 milliseconds from client request to response receipt. This is achieved by terminating TLS and serving cached, aggregated, or transformed responses from edge Point of Presence (PoP) servers located near the user.
Edge Caching is the practice of storing computed API responses on globally distributed Point of Presence (PoP) servers situated geographically close to users. By serving cached responses directly from edge memory, requests achieve sub-10ms latencies while offloading 95%+ of traffic from origin databases.
A cold start is the extra latency incurred when a serverless platform must initialize a new execution environment before handling a request. The runtime, dependencies, and application code are loaded from scratch, which can add hundreds of milliseconds or even seconds to the first response.
TLS handshake latency is the delay caused by negotiating an encrypted HTTPS connection before any application data is sent. The client and server exchange messages to agree on ciphers and verify certificates, costing one or more network round trips on top of TCP setup.
Ready-to-Use Edge Recipes
To solve sub 10ms api response time for mobile apps, never execute unauthenticated requests or embed private tokens directly in client bundles. RealComposer acts as a sub-10ms edge gateway running on Cloudflare Workers that securely injects credentials from your Secret Vault, normalizes responses, and prevents unauthorized API usage. Route calls through your RealComposer edge URL to guarantee complete privacy, robust origin validation, and low mobile latency.
To solve rest api edge cdn caching guide, never execute unauthenticated requests or embed private tokens directly in client bundles. RealComposer acts as a sub-10ms edge gateway running on Cloudflare Workers that securely injects credentials from your Secret Vault, normalizes responses, and prevents unauthorized API usage. Route calls through your RealComposer edge URL to guarantee complete privacy, robust origin validation, and low mobile latency.