Pressidium EDGE supports HTTP/2 and HTTP/3 automatically. The browser and EDGE negotiate the protocol used for each connection. No manual configuration is required.

  • HTTP/2 multiplexes requests over a single TCP connection and compresses HTTP fields.
  • HTTP/3 carries HTTP over QUIC, a secure transport built on UDP.
  • Automatic fallback allows a connection to use HTTP/2 or HTTP/1.1 when HTTP/3 is unavailable.

Understanding HTTP Protocols

HTTP/1.1

HTTP/1.1 supports persistent connections, allowing multiple requests and responses to use the same connection. However, it does not multiplex independent request and response streams in the same way as HTTP/2.

Compared with newer protocols, it generally requires more connections to load multiple page resources efficiently and does not use the header-compression mechanisms available in HTTP/2 and HTTP/3.

HTTP/2

HTTP/2 improves connection efficiency through:

  • Multiplexing: Multiple request and response streams can share one TCP connection.
  • Header compression: HPACK reduces repeated HTTP field data.
  • Binary framing: Messages are transferred using a structured binary format.

These capabilities can reduce connection overhead and allow page resources to load more efficiently.

HTTP/3 and QUIC

HTTP/3 carries HTTP traffic over QUIC, a secure and multiplexed transport built on UDP.

Its main capabilities include:

  • Independent streams: Packet loss affecting one stream does not require every other stream to wait.
  • Integrated TLS 1.3: Transport and security setup are coordinated through QUIC.
  • Connection migration: A connection can continue when the client’s network path changes, such as when moving between Wi-Fi and mobile data.
  • Reduced setup latency: QUIC can establish secure connections with fewer round trips in supported situations.

The actual performance benefit depends on the visitor’s network, browser, location, and the website’s content.

How EDGE Uses HTTP/2 and HTTP/3

EDGE and the visitor’s browser negotiate an available protocol for each connection.

When HTTP/3 is supported and successfully negotiated, the connection can use h3. Otherwise, the browser can connect using HTTP/2 or HTTP/1.1.

No manual configuration is required.

Protocol configuration

No manual protocol configuration is required. EDGE and the visitor’s browser negotiate the protocol available for each connection.

There are no documented per-site Dashboard controls for forcing or disabling HTTP/2 or HTTP/3. If HTTP/3 cannot be established, the connection can use HTTP/2 or HTTP/1.1 instead.

Verify the protocol in your browser

You can inspect the protocol used by individual requests in Chrome DevTools:

  1. Open the website in Chrome.
  2. Open Developer Tools.
  3. Select Network.
  4. Right-click the request-table headings and enable Protocol.
  5. Reload the page.
  6. Review the protocol shown for the document and other requests.

Common values include:

  • h3: HTTP/3
  • h2: HTTP/2
  • http/1.1: HTTP/1.1

Different resources on the same page may use different protocols, particularly when they are loaded from third-party domains.

Response headers

Response headers do not provide definitive proof of the protocol used for the current request. Use the browser’s Protocol column for verification.

An Alt-Svc response header containing an h3 value can advertise that HTTP/3 is available for future connections. Its presence does not mean that the current request was transferred over HTTP/3.

Do not rely on the Alt-Svc header alone when verifying the protocol. Use the browser’s Protocol column to identify the protocol used for the current request.

Common issues and solutions

HTTP/3 is not being used

Symptom: The browser shows h2 or http/1.1 instead of h3.

Likely causes:

  • The browser or operating system does not support HTTP/3.
  • The local network, VPN, firewall, or security software blocks QUIC traffic over UDP.
  • HTTP/3 was not negotiated for that connection.
  • The domain is not currently routing traffic through Pressidium EDGE.
  • The inspected resource is loaded from a third-party domain.

Resolution:

  1. Confirm that the website domain is connected to Pressidium EDGE.
  2. Test with an up-to-date browser.
  3. Reload the page and inspect the Protocol column again.
  4. Temporarily disable a VPN or test from another network.
  5. Check the main document request rather than only third-party assets.

Using HTTP/2 is a normal fallback and does not necessarily indicate a problem.

Performance has not improved

A newer protocol does not correct every source of poor performance.

Review:

  • page-cache behavior
  • origin response time
  • image and asset sizes
  • JavaScript and CSS processing
  • third-party services
  • plugin and theme processing
  • database activity
  • visitor location and network quality

Compare results using the same page, browser, location, and test conditions.

Need help?

Open a support request if the website consistently uses an unexpected protocol or experiences connection problems while served through EDGE.

Include:

  • Website name and domain
  • Date and approximate time
  • Browser name and version
  • Device and operating system
  • Network type or VPN use
  • Screenshot of the browser’s Protocol column
  • Description of the performance or connection issue

Where to go next