Loading a Web PageEvery step between typing a URL and seeing pixels.ComputingTyping an address sets off six distinct stages, each of which can fail on itsown.1DNS lookupThe name becomes an IP address, asking a resolver, then the root,2TCP connectionA three-way handshake opens a connection to that address on3TLS handshakeFor https, certificates are exchanged and checked, and an4HTTP requestThe browser sends GET / with its headers, cookies and what5Server responseA status code, headers and usually HTML come back.6RenderHTML is parsed into a DOM, CSS into styles, then layout, paint,WHERE IT USUALLY GOES WRONGSite not found → DNSCertificate warning → TLS404 or 500 → the request or the serverBlank page that loads → JavaScript, at renderSub-resources — CSS, JS, images, fonts — each repeat steps 2 to 5 ontheir own.Loading a Web Pagelearnposters.com
Loading a Web Page — printable computing wall chart from LearnPosters. Free vector PDF, US Letter and A4.

Loading a Web Page, step by step

Typing an address sets off six distinct stages, each of which can fail on its own.

  1. DNS lookupThe name becomes an IP address, asking a resolver, then the root, then the domain's servers.
  2. TCP connectionA three-way handshake opens a connection to that address on port 80 or 443.
  3. TLS handshakeFor https, certificates are exchanged and checked, and an encryption key is agreed.
  4. HTTP requestThe browser sends GET / with its headers, cookies and what formats it accepts.
  5. Server responseA status code, headers and usually HTML come back.
  6. RenderHTML is parsed into a DOM, CSS into styles, then layout, paint, and composite to the screen.

Where it usually goes wrong

  • Site not found → DNS
  • Certificate warning → TLS
  • 404 or 500 → the request or the server
  • Blank page that loads → JavaScript, at render

Sub-resources — CSS, JS, images, fonts — each repeat steps 2 to 5 on their own.

Questions about the Loading a Web Page poster

What’s on the Loading a Web Page poster?
6 numbered steps, with a full worked run-through. Typing an address sets off six distinct stages, each of which can fail on its own. DNS lookup — The name becomes an IP address, asking a resolver, then the root, then t…; TCP connection — A three-way handshake opens a connection to that address on port 80…; TLS handshake — For https, certificates are exchanged and checked, and an encryption…; HTTP request — The browser sends GET / with its headers, cookies and what formats it…; Server response — A status code, headers and usually HTML come back.; Render — HTML is parsed into a DOM, CSS into styles, then layout, paint, and composit…. Sub-resources — CSS, JS, images, fonts — each repeat steps 2 to 5 on their own.
Who is the Loading a Web Page poster for?
Loading a Web Page belongs to the Computing section rather than to a school year, because computing is not something one grade owns. Anyone learning the web can pin it up — a beginner, a student mid-course, or someone revising years later.
When should you use the Loading a Web Page poster?
When something is slow or broken, work down this list. The fault is always at one of these steps. A wall chart earns its place by being glanceable from where the work is happening, so Loading a Web Page belongs on the wall where that computing work actually happens, within glancing distance, rather than filed away.
What other posters go with Loading a Web Page?
Accessibility, ARIA and How a Browser Renders sit alongside Loading a Web Page in the Computing section. Printed together they make a wall rather than a single sheet, which is how a reference set actually gets used.AccessibilityARIAHow a Browser Renders
Is the Loading a Web Page poster free to download and print?
Yes. Loading a Web Page downloads as a free PDF with no account, no email and no watermark, like everything else in the Computing section. Print as many copies as you like for a home, a classroom, a library or a tutoring group; reselling the file is the only thing the licence rules out.Read the licence
What size does the Loading a Web Page poster print at?
Loading a Web Page is a vector PDF laid out for US Letter, and prints on A4 with Fit to page — the same file, no separate download. Because every mark on it is drawn rather than photographed, it stays sharp enlarged to A3, A2 or A1 at a copy shop. Colour carries emphasis only, so a greyscale print of Loading a Web Page loses nothing.Printing guide

Related posters

Charts that sit alongside Loading a Web Page on the same wall.

Browse every Computing poster, or start from the full catalogue.