Kraken.io Image Optimizer – Compress, Convert to WebP & AVIF, Resize & Bulk Optimize

79 Quality Score

Active Installs

18/30

With 9,000 active installs, the plugin has a modest user base compared to category leaders like Smush and Imagify, each with one million installs, which suggests a niche following rather than mainstream adoption.

Update Freshness

25/25

The plugin was last updated on 2026-06-22 and is tested against WordPress 7.0, signalling that the developer is actively maintaining it for current and upcoming core releases.

User Rating

14/15

A score of 90 out of 100 from 119 ratings indicates strong satisfaction among the users who have reviewed it, though the sample size is relatively small.

Support Health

8/15

With zero support threads recorded, there is no data to confirm responsiveness, which makes it harder to judge how the developer handles user issues.

WP Compatibility

15/15

Full marks here: the plugin requires only PHP 5.6 and WordPress 4.9, making it compatible with virtually any environment still running today.

Scores higher than 71% of indexed plugins

About

Optimize images automatically — compress, resize and convert to WebP, AVIF & more with Kraken.io. Faster pages, smaller files, same quality.

Active Installs 10k+

Rating ★★★★½ 4.5/5

Last Updated 2026-06-22 9:39am GMT

Requires WordPress 4.9+

Tested Up To 7.0.4

Requires PHP 5.6+

Security History

3 known vulnerabilities, all patched

1 High 2 Medium

Most recent: February 1, 2023

View details ▸

What It Does

Kraken.io Image Optimizer connects your WordPress media library to the Kraken.io API to compress images, resize them, and convert them into modern formats like WebP and AVIF. Image processing happens on Kraken.io's servers rather than your own, which keeps local CPU and memory usage low even during bulk optimization runs. It handles individual uploads as well as bulk optimization of existing media library files.

Who It's For

This plugin is a good fit for site owners who already use or are willing to pay for the Kraken.io service and want server-side image processing without taxing their hosting environment. It works well for image-heavy sites such as photography portfolios, real estate listings, ecommerce stores, and news or magazine publishers where bulk optimization and format conversion to WebP or AVIF matter. Photographers and product-heavy sites that need consistent, high-quality compression at scale will benefit most.

Who Should Skip It

If you want a free, self-contained image optimizer that runs entirely on your own server, this plugin is not the right choice because it depends on the paid Kraken.io API for processing. Sites with very small image libraries or strict budgets will get more value from free alternatives like Smush or ShortPixel's free tier.

The Bottom Line

Kraken.io Image Optimizer is a well-maintained, highly rated plugin that delivers exactly what Kraken.io customers expect: dependable, server-side image compression and next-gen format conversion. The trade-off is that it is a paid, API-dependent tool with a small install base and no trackable support history. Pick it if you are already invested in the Kraken.io ecosystem or need offloaded processing; otherwise, one of the larger alternatives will give you more features for less money.

Pick Smush if you want a free, widely used optimizer with built-in lazy load and CDN options that runs locally without a paid API.

Converter for Media – Optimize images | Convert WebP & AVIF 88/100

Choose Converter for Media if your only goal is to serve WebP or AVIF versions of existing images and you do not need heavy compression features.

Imagify Image Optimization: Optimize Images | Compress & Convert to WebP/AVIF 87/100

Go with Imagify if you want a paid API-based optimizer from the same team as WP Rocket, with similar server-side processing and a more mainstream install base.

ShortPixel Image Optimizer – Optimize Images, Convert WebP & AVIF 86/100

ShortPixel is worth picking if you want a generous free monthly quota plus paid tiers, with PDF optimization included alongside images.

Optimole – Optimize Images | Convert WebP & AVIF | CDN & Lazy Load | Image Optimization 85/100

Choose Optimole if you want image optimization combined with a built-in CDN and real-time on-the-fly resizing rather than a bulk-only approach.