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Sreekanth Kuruba
Sreekanth Kuruba

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HTTP/1.1 vs HTTP/2 vs HTTP/3 – Which One Are You Still Using in 2025?

🚀 Networking for DevOps & SRE – 2025 Edition • Part 2/10

Most teams think they’ve already moved to HTTP/2 or HTTP/3.

But when we checked real production traffic in 2025, the truth was surprising:

We pulled protocol stats from our CDN + load balancer logs...

63% of all requests were still hitting us over HTTP/1.1 — mostly from corporate proxies, middleboxes, and legacy devices.

Pie chart showing HTTP protocol distribution: 63% HTTP/1.1, 25% HTTP/2, and 12% HTTP/3, based on real production traffic analysis

That means 2 out of every 3 requests were paying an unnecessary 150–300ms latency tax just because outdated protocols were still in the path.

The Web’s 2025 Protocol Reality Check

All three versions move data between browser and backend.
But how they do it — TCP vs multiplexing vs QUIC — creates massive differences in:

  • Page load speed
  • API latency
  • Core Web Vitals
  • CDN routing efficiency
  • Mobile reliability

Here’s the 2025 snapshot:

📊 HTTP/1.1 vs HTTP/2 vs HTTP/3 (2025 Edition)

Feature HTTP/1.1 (1997) HTTP/2 (2015) HTTP/3 (2022+, QUIC)
Transport TCP TCP UDP (QUIC)
Multiplexing No Yes Yes (independent streams)
HOL Blocking Yes Yes (TCP) None
Header Compression None HPACK QPACK
Connection Setup 1–3 RTT 1–3 RTT 0–1 RTT
Mobile Performance Poor Decent Best
Real Adoption (2025) 15–20% 60–65% 25–30% and rising
Browser Support 100% ~98% ~95–97%

🦕 HTTP/1.1 – The Dinosaur That Refuses to Die

Why it still dominates:

  • Corporate proxies downgrade connections
  • Old load balancers downgrade traffic back to HTTP/1.1
  • Cheap hosting providers
  • Legacy browsers & IoT devices
  • Internal APIs nobody migrated

Problems:

  • No multiplexing
  • HOL blocking
  • Browser opens 6 parallel connections
  • Massive header repetition

If you still rely on HTTP/1.1 in 2025, you are paying a latency tax every single day.

HTTP/2 – The Multiplexing Hero (With One Big Problem)

HTTP/2 solved a lot:

  • Binary framing
  • Multiplexing
  • Header compression
  • Single connection

But it still suffers from TCP Head-of-Line Blocking:

One lost packet → all streams wait.

On flaky networks (mobile, 3–5% packet loss), H2 often performs worse than people expect.

Still excellent for: CDNs, production APIs, stable networks.

HTTP/3 – QUIC Is the Real Upgrade

HTTP/3 ditches TCP entirely and uses QUIC over UDP.

Big wins:

  • 0-RTT resume
  • No HOL blocking
  • Faster handshakes
  • Better encryption (TLS 1.3 built-in)
  • Superior mobile performance
  • Stable under packet loss

This is the first protocol designed for modern, mobile, global internet traffic.

📈 Real 2025 Performance Results

Scenario HTTP/1.1 HTTP/2 HTTP/3
100 small assets 4–6s ~1.2s ~0.9s
3% packet loss Terrible Bad Good
Flaky mobile Painful Okay Best
First load Slow Slow Fastest
Repeat visits ~Same ~Same Instant (0-RTT)

The Problem Nobody Mentions

Even if your CDN + app support HTTP/3:

Many users still fall back to 1.1 or 2.0 due to network intermediaries.

Common blockers:

  • Corporate firewalls
  • Middleboxes that strip UDP
  • Legacy devices
  • Some enterprise proxies
  • Outdated routers
  • Misconfigured hosting

This is why simply enabling HTTP/3 is not enough – everything in the path must support it.

So What Should You Use in 2025?

HTTP/1.1 → Only for legacy systems

Or internal APIs that never changed.
HTTP/2 → Still excellent and widely reliable

Stable, cheap, widely supported.
HTTP/3 → Enable it everywhere you can

(Cloudflare, CloudFront, Fastly, Akamai, Bunny — all support it now)
Quick Checklist to Move to HTTP/3 (2025)

CDN

  • Cloudflare → Enable QUIC + HTTP/3
  • CloudFront → Supported on new distributions
  • Fastly/Akamai/Bunny → Native support

Self-Hosted

  • Nginx 1.25+ QUIC
  • Caddy 2.6+ (auto HTTP/3)
  • Traefik v3
  • LiteSpeed / OpenLiteSpeed

Backend

  • Node.js 21+ with QUIC
  • Go, Rust, Java (Netty) → great QUIC libraries
  • Python → aioquic or reverse proxy

Final Verdict (2025)

HTTP/1.1 → Legacy tech

HTTP/2 → Today’s safe default

HTTP/3 → Today’s performance baseline

HTTP/3 isn’t “future tech” anymore - it’s the baseline for fast global apps in 2025.

The question isn’t if you should upgrade…

It’s how much faster your users will be when you do.


Part of the “Networking for DevOps & SRE – 2025 Edition” series

Part 1 → HTTP/HTTPS/TCP/UDP Foundations

Part 3 → TLS 1.2 vs TLS 1.3 in Production: (drops Next Tuesday 7:30 PM IST)
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Top comments (1)

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Sreekanth Kuruba • Edited

What’s the majority of your production traffic actually running on in late 2025?

  • Still mostly HTTP/1.1 (proxies, legacy, life is pain)
  • Mostly HTTP/2 (good enough, no drama)
  • Mostly HTTP/3 (QUIC finally won)
  • Chaos mix of all three
  • I have no idea (send help)

Drop the line that matches your reality — let’s see the real 2025 numbers in the comments!