Wednesday, June 3, 2015

HTTP/2 (and H2O) improves user experience over HTTP/1.1 or SPDY

HTTP/2 is expected to offer better user experience than HTTP/1.1, the unanswered question is how much the benefit is in practice.

Tonight I have given a presentation regarding the issue, showing HTTP/2 performance of H2O HTTP server at, a popular technology meetup at Tokyo. This blog post is a summary of the presentation at the meetup, following my recent blog post about the prioritization logic of HTTP/2 and web browser implementations.

Test Scenario:
  • a modified version of (<script> tags moved into <head>)
    • contains 5 CSS files
    • 8 script files in <head>, including a minified version of jquery.js
    • contains 18 not-blocking assets (e.g. images files), both small and large
  • client: Chrome/43 and Firefox/38
  • server: Nginx/1.9.1 and H2O/HEAD
  • network: dedicated virtual network to avoid noise; 100ms latency (typical for 4G mobile) added artificially using tc disc command

Benchmark Results:


When using H2O (and HTTP/2) with optimal settings, the first-paint times are reduced by about 30% when compared to HTTP/1.1 or SPDY/3.1.

First-paint time is a good index of user experience; it shows the timing when the user sees the page being rendered for the first time (or when all assets that block rendering arrives at the client side) since he/she triggered the navigation.

The improvements are due to the fact that Firefox (or Chrome with H2O's http2-reprioritize-blocking-assets configuration directive set to ON) downloads assets files that block rendering (e.g. CSS or JS files) before other asset files (e.g. images).


With the benchmark showing 30% reduction in first-paint time, it is obvious that HTTP/2 (implemented by H2O) is offering superior performance against the protocols of previous generations. However, implementations might not be mature enough to offer such boost in performance (as discussed in recent blog post, Chrome has issues with its prioritization logic which is worked around by the configuration directive of H2O; Nginx does not prioritize the streams even though such feature is available in SPDY).

For the time being it is suggested that users conduct benchmarks to see if their applications actually become faster, or consult the developers of the HTTP servers for benchmark results.

Or, you can use H2O, which has been hereby shown to provide good performance under the described scenario :-)

PS. The presentation slides used at the meetup is available here:


  1. saat ini kebutuhan akan priduk bahan bangunan sangat meningkat pesat yang didukung dengan program pemerintah
    dalam pembangunan infrastruktur negara. Dengan program ini maka pembangunan di setiap lini terutama di bagian pinggiran menjadi
    prioritas dalam pembangunan. Pembangunan ifrastuktur ini sangat berpengaruh terhadap harga bahan bangunan di daerah pinggiran
    seperti di daerah papua yang mana dahulu disana harga semen bisa mencapai 800 ribu sampai dengan 1 juta sekarang sudah turun dan setara
    dengan daerah lainnya.

    Geliat pembangunan infrastruktur ini juga berimbas pada toko bahan bangunan online
    yang mana banyak sekali permintaan dari
    para kontraktor untuk proyek yang mereka kerjakan. Produk material bangunan yang mengalami peningkatan saat ini seperti produk
    atap dan genteng, produk ventilator, bata ringan dan lain sebagainya.

  2. Get best At&t Email support services in USA by calling 1-877-363-0097 toll-free number for At&t email Technical Support Number, At&t email support number.

  3. Become a professional sales executive and distribution manager by pursuing high-quality SAP SD certification training course from talent magnifier. Take a demo class free in Talent Magnifier.
    visit us -Website

  4. Join VBA Macros Training in Delhiin Talent Magnifier with 100% job placement assistance.
    Intrested candidate can Contact Us @

  5. Talent Magnifier is a leading Certification Courses in HR for Freshers. We provide corporate training with Live Practicals in All Modules?

  6. Thank you for sharing the article! Glad to find the post!
    celebrity net worth

  7. Expect Talent Magnifier's Basic Computer Training Courses For Freshers -Enroll Now - Free Demo Classes.
    For more info - Click Here

  8. Contact +1(888) 963-7228 HP Laptop Support Phone Number for get HP Help United states. If you perspective errors like software installation, configuration, Troubleshooting then you can solve the issues remotely by the Technician.

  9. An aspiring candidate who wants to learn excel can visit Talent Magnifier for the Excel Courses in Delhi. Here you will get the training to have the advanced level of excellence in MS Excel.For more details visit us @


Note: Only a member of this blog may post a comment.