WordPress Image Optimizer

WordPress Image Optimizer

Convert and optimize images for different uses with this wordpress image optimizer. Transform images between formats while maintaining quality.

When to Use This Tool

Optimizing images specifically for WordPress sites.

Key Benefits

• Faster WordPress sites
• Better hosting costs
• Improved rankings
• Responsive images

Pro Tip

WordPress creates multiple sizes automatically. Optimize originals before uploading.

Supported Formats

Format	Best For	Supports
JPEG	Photos	Lossy compression
PNG	Graphics, screenshots	Transparency, lossless
WebP	Web images	Both lossy and transparency
GIF	Animations	Limited colors

Optimization Tips

1. Use JPEG for photos to reduce file size 2. Choose PNG when you need transparency 3. Consider WebP for modern browsers 4. Compress images before uploading to websites

Images in WordPress

WordPress generates multiple sizes of every upload automatically, which means an oversized original multiplies across the media library.

Registered size	Default dimensions
Thumbnail	150 × 150 (cropped)
Medium	300 × 300 max
Medium large	768px wide
Large	1024 × 1024 max
1536×1536	1536px max
2048×2048	2048px max

Uploading a 5 MB camera original therefore produces six derivatives plus the original. Resize to 1920px and compress before uploading and you cut the whole set proportionally.

WordPress 5.8+ serves WebP where the browser supports it, and 6.1+ can convert uploads to WebP automatically. Combined with srcset — which core emits by default — that covers most of what an image optimisation plugin does, at no plugin cost.

Set big_image_size_threshold to cap the stored original if contributors upload from phones.

Sizing Before Compressing

Resizing beats compressing. Halving an image's dimensions removes 75% of its pixels, which no quality setting can match, and a 4000px photo displayed at 800px is wasting 96% of what it downloads.

Displayed at	Serve (1×)	Serve (2× for retina)
400px	400px	800px
800px	800px	1600px
1200px	1200px	2400px

Above 2× there is no visible benefit on any current display, and the file size keeps rising.

Quality Settings That Hold Up

Setting	Looks	Use for
95–100	Indistinguishable, large	Masters and print
80–90	Very good	Hero images, product photography
70–80	Good	Most web content
50–70	Visible artefacts on detail	Thumbnails
Below 50	Obvious	Nothing

Around 75–85 is where the curve bends: below it quality falls quickly, above it file size rises quickly for no visible gain.

Everything Runs Locally

Conversion and compression here use a canvas in your own tab. No file is uploaded, nothing is stored, and the work continues offline once the page has loaded. That is worth knowing for anything containing faces, documents or unreleased work — most online image tools upload by necessity, because they process server-side.

Getting the Rest of the Win

• Serve modern formats with a fallback. with AVIF, then WebP, then JPG.
• Always set width and height. Without them the page reflows on load, which

Google measures as Cumulative Layout Shift.

• Lazy-load below the fold — and never the hero, since loading="lazy" on it delays

the exact element Largest Contentful Paint measures.

• Strip metadata. EXIF can carry GPS coordinates and adds weight to every copy.