ProRank vs Optimole: image compression compared
Optimole optimizes images in its cloud and serves them from its CDN. ProRank keeps optimized files on your own server. Here is what that difference means, with our own compression test and its limits.
- Features and prices checked on .
- Compression test run by ProRank on , with Optimole 4.2.1.
ProRank and Optimole in brief
Optimole serves images from Amazon CloudFront, resized for each visitor’s screen and converted to WebP or AVIF on the fly. The free plan includes the CDN for up to 2,000 visits a month, and paid plans are priced by visits, not images.
Optimized images live on Optimole’s CDN rather than on your server. If you deactivate the plugin, Optimole’s documentation says image URLs return to your original files; images moved to Optimole Cloud, a paid feature, need moving back before you cancel. It has no page caching or SEO features.
ProRank compresses on your own server in the free plan, or in its cloud on paid plans, and keeps the files on your server. It does not run its own image CDN, but works with the CDN you already use.
File size reduction in our test
Three 2400px photos, against the original JPEG. Higher means smaller files; the larger reduction is in bold.
| Output format | ProRank | Optimole |
|---|---|---|
| JPEG | 79.4% | 68.1% |
| WebP | 82.7% | 79.9% |
| AVIF | 91.7% | 76.6% |
| JPEG XL | 55.9% | Not tested |
- Of the three formats both were tested on, ProRank made smaller files in JPEG and WebP and AVIF.
- One lab test by ProRank; visual quality was not scored. Details are below.
How the image test was run
- Run by
- ProRank, on 16 February 2026. This is our own test, not an independent one.
- Images
- Three 2400px-wide JPEG photographs (2,766 KB in total)
- Compression
- Each plugin’s own lossy compression; ProRank used its paid cloud optimizer (cjpegli for JPEG, Sharp for WebP and AVIF, cjxl for JPEG XL).
- Measured
- Size reduction against the original JPEG. Higher means smaller files; visual quality was not scored.
- Versions
- Optimole 4.2.1 (the current version is 4.2.20).
- Figures shown
- Our two records of this test disagree on some numbers. Where they do, this page shows the figure less favorable to ProRank.
- Raw files
- Not published.
- Optimole in this test
- Optimole’s AVIF files were larger than its WebP files in this test (76.6% against 79.9% reduction).
Features compared
What each plugin offers today, and which ProRank plan you need for it. Optimole is checked against its own website and documentation.
| Feature | ProRank | Optimole |
|---|---|---|
| Compression | ||
| Lossy compression | Free plan | Included |
| WebP conversion | Free plan | Included |
| AVIF conversion | Free plan | Included |
| Bulk-optimize the media library | Free plan | Included |
| Where images live | ||
| Optimized files kept on your server | Free plan | Not includedServed from Optimole’s CDN |
| Works without an account or API key | Free planOn-server compression | Not includedCloud service |
| CDN delivery | Free planYour own CDN; no ProRank CDN | IncludedCloudFront, free plan too |
| Lazy loading | Free plan | Included |
| Beyond images | ||
| Page caching | Free plan | Not included |
| Critical CSS | Pro plan | Not included |
| SEO titles, meta and sitemaps | Free plan | Not included |
Checked on against Optimole’s own pages (version 4.2.20):
- Optimole on WordPress.org (version 4.2.20)
- Optimole pricing
- Optimole docs: which plan do I need
- Optimole docs: what happens when you deactivate
- Optimole docs: supported formats
“Paid plan” means the feature needs Optimole’s paid version; “Paid add-on” means a separate paid product or service. “Not included” means the vendor’s own feature list and documentation did not offer it on that date. Rows we could not confirm are left out. ProRank’s plan labels come from our pricing page. Plugins change often; if you spot something out of date, tell us and we will correct it.
The image settings in ProRank
Image optimization sits with ProRank’s other speed settings and shows how much of your media library is converted and how much space it saved.
What each costs
Both have a starting point you can try first. Competitor prices are as shown on their own pricing pages on . Prices change and sale prices end, so check before you buy.
ProRank SEO
- Free
- Free, on WordPress.org
- Pro
- $99 a year, 1 site
- Business
- $199 a year, 5 sites
- Agency
- $399 a year, 25 sites
US dollars, excluding VAT, billed yearly. 30-day money-back guarantee. The test used ProRank’s cloud optimizer, which comes with paid plans: 5,000 images a year on Pro (up to 416 a month), 20,000 on Business and 100,000 on Agency. The free plugin compresses on your own server.
Optimole
Free version on WordPress.org. Paid version from:
$19.08 a month, billed yearly
Starter plan: 48,000 visits a month, unlimited images and sites ($22.90 month to month). 7-day money-back guarantee. Free: 2,000 visits a month. Shown in US dollars; other countries see other currencies.
Try ProRank on your own images
The free plugin compresses images on your own server and converts them to WebP and AVIF, alongside page caching and the SEO tools.