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Bianca Rus
Bianca Rus

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JPEG vs WebP vs AVIF in WordPress: Real Benchmark Data (4 Plugins Tested)

TL;DR: I benchmarked 4 image optimization plugins on the exact same WordPress install with the same source image, all tested on lossy mode. AVIF is the clear winner format, up to 91% compression. The differences between plugins are bigger than the marketing suggests. Full data tables below

Why I Did This

I got tired of vague comparisons with no real numbers. So I set up a controlled test, same server, same WordPress install, same source image, and ran every major image optimization plugin through the same benchmark. No affiliate links. Just numbers.


Test Setup

Source image: Single JPEG, 2400×1590px — a real-world photo, not a tiny thumbnail.

Plugins tested: ShortPixel, Imagify, Optimole, EWWW Image Optimizer

Method: Each plugin processed the same source file with lossy mode (most aggressive available). Output files downloaded and measured directly.


Results

JPEG Compression (Lossy)

Plugin Output Reduction Verdict
🏆 ShortPixel (Lossy) 89 KB 82.0% 🟢🟢🟢🟢🟢
🥈 Imagify (Lossy) 119 KB 75.9% 🟡🟡🟡🟡
🥉 Optimole 128 KB 74.1% 🟡🟡🟡
EWWW (Premium Lossy) 154 KB 68.8% 🔴🔴

WebP Compression (Lossy)

Plugin Output Reduction Verdict
🏆 ShortPixel 55 KB 88.9% 🟢🟢🟢🟢🟢
🥈 Imagify 74 KB 85.0% 🟡🟡🟡🟡
🥉 Optimole 79 KB 84.0% 🟡🟡🟡
EWWW 91 KB 81.6% 🔴🔴

AVIF Compression (Lossy)

Plugin Output Reduction Verdict
🥇 ShortPixel 43 KB 91.3% 🟢🟢🟢🟢🟢
🥈 Imagify 69 KB 86.0% 🟡🟡🟡🟡
🥉 Optimole 133 KB 73.1% 🔴🔴
EWWW Paid addon

AVIF delivers 91% compression vs 82% for JPEG. Your 494 KB photo becomes 43 KB. Most plugins either don't offer it or lock it behind a paid tier.


Plugin-by-Plugin Breakdown

ShortPixel

Best results across all three formats and by far the easiest to set up — installed it, picked lossy, hit bulk optimize, done. No upsells, no locked formats, no second-guessing. If you're starting fresh, start here.

Imagify

Clean interface, smooth setup, decent results — just not at ShortPixel's level in my tests. If you're already on it and happy, no urgent reason to switch.

Optimole

Works more like a CDN than a traditional optimizer, which is genuinely useful on shared hosting. Compression was fine but unremarkable, and I felt like I had less control over what was happening under the hood.

EWWW Image Optimizer

The most complex to configure by far, and AVIF is locked behind a paid upgrade which was frustrating to discover after setup. To be fair, the premium tier does unlock better compression — but with ShortPixel you get all of that out of the box.


✅ Quick Checklist: Before You Pick an Image Optimization Plugin

Before committing to any plugin, here's what I'd check:

  • Does it support AVIF? Not as a paid addon — out of the box. In 2026 this should be a baseline, not a premium feature.
  • Is lossy mode actually aggressive? Some plugins label things "aggressive" but the output tells a different story. Check the actual file sizes.
  • Does it bulk optimize existing images? Useful if you're migrating or switching plugins mid-way through a project.
  • How much manual setup does it need? If you have to spend 30 minutes reading docs just to get started, that's a red flag for a client site.
  • Are modern formats (WebP/AVIF) served automatically? The plugin should handle format switching per browser — you shouldn't need to configure that manually.
  • What happens when you hit the free tier limit? Some plugins silently stop optimizing. Worth knowing before you go live.

For me, ShortPixel ticked every single one of these without any surprises. But run through this list with whatever plugin you're considering — the answers will tell you a lot.


Bottom Line

Take these numbers as a reference, not a verdict. The best plugin is ultimately the one that fits your workflow, your budget, and your site. Curious what others are running in 2026 — let me know in the comments.


Methodology

  • Same source JPEG (494 KB, 2400×1590px) used for all plugins
  • Each plugin processed with lossy mode (most aggressive setting available per plugin)
  • Output files downloaded and measured directly (macOS Finder — exact byte counts)
  • No resizing applied — same dimensions in, same dimensions out
  • AVIF and WebP tested where available; noted where locked behind paid tiers

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