Epic: #15
Block: 8 — How Browsers Work: Architecture to Pixels
Series order: 15 of 18
Description
The sequence of events inside the browser between pressing Enter and receiving the first byte of HTML — a journey that crosses multiple processes and involves security checks, MIME detection, and renderer preparation.
Key topics
- UI thread: handling the keypress, deciding if the input is a URL or a search query
- Network thread: DNS lookup, TCP+TLS connection, HTTP request
- Safe Browsing check: the hash-based phishing/malware lookup that happens in parallel
- The response headers arrive: before the body, the browser has to decide what to do
- MIME type detection:
Content-Type check and MIME sniffing to identify the resource type
- Renderer process preparation: Chrome speculatively launches a renderer process while waiting for the response
- Navigation commit: the moment ownership transfers from the network thread to the renderer
- The browser process → renderer process IPC: sending the data stream across process boundaries
Epic: #15
Block: 8 — How Browsers Work: Architecture to Pixels
Series order: 15 of 18
Description
The sequence of events inside the browser between pressing Enter and receiving the first byte of HTML — a journey that crosses multiple processes and involves security checks, MIME detection, and renderer preparation.
Key topics
Content-Typecheck and MIME sniffing to identify the resource type