What Happens When You Type google.com and Press Enter?
A microsecond-by-microsecond journey across keyboard hardware, operating system kernels, undersea fiber optic cables, TLS handshakes, and GPU browser rendering engines.
1. Keystroke & URL Parsing
The keyboard generates an electrical scan code, the OS dispatches a key event, and the browser checks whether you typed a URL or a search query.
The browser UI thread checks the address bar string against HSTS preload lists (Strict-Transport-Security) to force HTTPS before sending any unencrypted packet. Auto-complete and history algorithms are queried.
2. DNS Resolution & ARP Cache
Your device checks browser cache, OS resolver cache, and queries the recursive DNS server to find Google's IP address (e.g. 142.250.190.46).
The OS network stack calls getaddrinfo(). If not cached, a UDP port 53 query is sent to 1.1.1.1 or 8.8.8.8. The host also looks up the local router's MAC address via ARP (Address Resolution Protocol) broadcast.
3. TCP 3-Way Handshake & TLS 1.3 Key Exchange
Your computer opens a secure encrypted cryptographic tunnel with Google's edge server.
A TCP SYN packet is sent; Google responds with SYN-ACK; client sends ACK. In TLS 1.3, the ClientHello immediately includes Diffie-Hellman public key shares (1-RTT), negotiating AES-GCM-256 session keys in a single roundtrip.
4. Undersea Routing & BGP Anycast
Packets pulse as laser light across thousands of miles of submarine fiber-optic cables along optimal BGP routing paths.
Autonomous Systems (AS) route packets through Tier-1 telecom backbones. BGP Anycast routes the request to the geographically closest Google Edge Point of Presence (PoP) in Jakarta or Singapore.
5. Server Processing & HTTP/3 QUIC Streaming
Google's edge load balancer routes the HTTP GET request to web servers which stream HTML bytes back.
Borg cluster orchestration routes the query to index ranking services. The edge server immediately streams back gzip/brotli-compressed HTML chunks using HTTP/3 (UDP QUIC multiplexing).
6. Critical Rendering Path & GPU Composite
Chromium parses the HTML into a DOM tree, constructs the Render Tree, computes layout geometry, and the GPU paints pixels to your display.
HTML tokenizer builds the DOM; CSS parser constructs the CSSOM. The Blink engine calculates layout geometry, rasterizes layer tiles using GPU Skia/DirectX 12 shaders, and composites the final frame at 120Hz.