About this plugin
Harvify Image Optimizer helps WordPress administrators convert Media Library images to modern WebP and AVIF formats without running heavy compression work inside PHP.
The plugin scans lightweight attachment metadata first, then your browser converts selected images in a small queue. Images are processed with Web Workers and OffscreenCanvas where available, uploaded back through authenticated WordPress REST API requests, and released from browser memory as each item finishes.
This client-side approach is designed for shared hosting environments where PHP memory limits and execution timeouts can interrupt large image optimization jobs.
Key features
- Convert JPEG, PNG, WebP, and AVIF source images to WebP or AVIF.
- Scan one source format at a time so existing target-format images are not
accidentally reprocessed.
- Select a few images for a test run before processing the full queue.
- Skip small files, very large images, selected upload paths, or filename
patterns.
- Lazy-load images on the front end.
- Media Library “Optimize now” row action — convert and replace a single
image straight from the Media Library list, using the same in-browser engine
as the bulk queue.
- PNG to JPEG preset — one click in the optimizer switches PNG sources to a
JPEG target, which is usually far smaller for photographs.
- Restore an image you replaced — put the original file back from the image’s
Media Library row, or from its row in the optimizer, at any time later, in the
free tier.
- Total optimized and KB saved — on the Insights tab: how many images you have
optimised and how much space that has saved, totalled across the whole library.
- Resize on upload — optionally downscale new JPEG, PNG and WebP uploads that
are larger than a size you choose (GIFs are never touched). Off by default.
- Adjust quality with a slider, and queue concurrency, from the admin screen.
- Save queue state in the browser with IndexedDB so work can resume after
interruption.
- Keep wp-admin responsive by doing conversion work in browser workers.
- Process images locally in your browser without using an external optimization
API.
- Optional original-file deletion, disabled by default.
Pro features (Harvify Pro Bundle)
- Automatic front-end delivery — your pages serve WebP/AVIF through a
element with the original as the fallback, so browsers that cannot
read the new formats still get an image. Covers post content and featured
images.
- Keep originals, and restore — convert to sidecar variants instead of
replacing the file, then restore a single image or bulk-restore every
generated variant in one action.
- Auto-queue new uploads — images uploaded from now on are marked for the
next run, so the library does not drift back out of date.
- Media Library status column — see at a glance which attachments are
optimised, and which queue items are WooCommerce product images.
- Savings reports with CSV export — how much space you have actually
reclaimed, per format, plus a debug log you can copy into a support request.
- Per-format quality control — separate WebP, AVIF and JPEG quality settings
rather than one slider for everything.
Privacy and external services
Harvify Image Optimizer does not send images to a third-party compression service, load scripts from external CDNs, or track usage. Images are fetched by your browser from your own WordPress site and uploaded back to your own WordPress REST API.
AVIF encoding uses bundled WebAssembly encoder files. 0 licensed @jsquash/avif single-thread encoder, with the earlier bundled wasm-avif encoder retained as a local fallback.
External services
This plugin connects to Freemius, the licensing and update service Harvify uses to
sell and deliver the Pro tier of its plugins.
Nothing is sent to Freemius unless you choose to send it. On activation you are shown
Freemius’s standard opt-in screen. Until you answer it a fresh install makes no
outbound request at all, and if you choose Skip the free tier stays fully usable
and still sends nothing. Data is transmitted only when you take one of these
actions:
- You click “Allow & Continue” on the Freemius opt-in screen. This sends your
site address, your administrator email address, and your WordPress, PHP and active
plugin/theme details, so Harvify can provide support and know which environments to
test against. Skipping that screen sends nothing and leaves the plugin working
normally.
- You enter a Pro Bundle licence key. This sends the key together with your site
address so the licence can be activated for that site. While a licence is active the
site also re-checks periodically that it is still valid and whether a Pro update is
available.
Service provided by Freemius, Inc. com/
com/terms/
com/privacy/
Image conversion
Conversion runs entirely inside your own browser using WebAssembly encoders bundled
with the plugin. Images are read from, and written back to, your own WordPress site.
No image is sent to any third-party service and no external CDN is used.