Pro features and licensing
Everything needed to optimize and serve your images is free, AVIF included. BytCrush Pro adds tools for sites where every kilobyte and every Core Web Vitals point counts.
| Feature | Free | Pro |
|---|---|---|
| One-click bulk optimization | ✓ | ✓ |
| Automatic optimization on upload | ✓ | ✓ |
| Original backups and one-click restore | ✓ | ✓ |
| Gentle and Balanced compression | ✓ | ✓ |
| WebP conversion and delivery | ✓ | ✓ |
| AVIF conversion and delivery | ✓ | ✓ |
| Resize oversized images | ✓ | ✓ |
| Metadata stripping (colour profile kept) | ✓ | ✓ |
| Background optimization (close the tab) | ✓ | ✓ |
| Page speed audit and one-click fixes | ✓ | |
| Ultra compression level | ✓ | |
| Smart target file size | ✓ | |
| Priority support | ✓ |
How Pro is delivered
Pro is the premium version of the plugin, downloaded from Freemius after purchase. It replaces the free version from WordPress.org and needs an active license.
| You run | What you see |
|---|---|
| The free plugin | No Page audit tab, no Smart target row, no Ultra level. A Go Pro tab and a PRO card on the dashboard. The header badge says Free. |
| The Pro plugin without an active license | A Page audit tab with a PRO badge, showing an example report and Unlock the page audit. Smart target file size is visible but greyed out. No Ultra level. |
| The Pro plugin with an active license | Everything unlocked. The header badge says Pro and the Go Pro tab is gone. |
Page speed audit
BytCrush → Page audit shows which images slow a page down, and fixes most of them in one click. It needs no API keys, and nothing is sent outside your site.
Running a scan
- Pick a page from the list (Home page, Shop if WooCommerce is active, and your 30 most recently updated pages, posts and products), or choose Another address… and type the URL.
- Click Scan page.
The audit opens the page in your browser, inside the admin screen, twice:
- on a phone, 390 px wide;
- on a laptop, 1440 px wide.
Each time it finds the main image, scrolls through every image and measures how large each is shown. It then checks every image against your Media Library. The admin bar is hidden in the scanned page.
Only pages on your own site (same domain and port) can be scanned. A scan stops after 45 seconds. If the page can't be shown in a frame, for example because a security plugin sends X-Frame-Options or the page redirects to another domain, the scan fails with a message saying so.
The report
The report gives a score from 0 to 100 for phones and for laptops: Great (90 and up), Needs work (50 to 89) or Poor. It also shows the page's image weight, the potential savings and how many images were checked.
The score is made up of:
- 70 points for image bytes (how much of the weight could be saved);
- 15 points for the main image's timing;
- 8 points for images having width and height;
- 7 points for lazy-loading images below the fold.
Each problem is listed as Critical, Warning or Tip, with the images it affects and, where possible, a fix button. Fix all applies every available fix at once. Scan again checks the result. Your last 15 scans are listed under Recent scans.
| Problem | Fix button | What the fix does |
|---|---|---|
| The main image loads late (it's lazy-loaded) or Give the main image priority | Load it first | On that page, removes lazy-loading from the main image and adds fetchpriority="high". |
| N images haven't been optimized yet | Optimize N images | Optimizes those images now. |
| N images are bigger than they're shown | Serve the right size | On that page, gives those images a sizes attribute based on the widths measured on phones and laptops, and adds a srcset if they lack one, so each device downloads a file that fits. |
| N images have no width and height | Add missing dimensions | Switches on the Missing width & height automatic fix. |
| N images below the fold load immediately | Lazy-load offscreen images | On that page, lazy-loads exactly those images, and switches on the Lazy-load offscreen images automatic fix. |
| N background images aren't converted to WebP, or WebP versions exist but images are delivered in their original format | Switch to server rewrite | Sets Delivery method to Server rewrite. Only offered on Apache or LiteSpeed. On other servers the report explains that rewrite rules are needed in your Nginx or CDN configuration. |
| N images are still over 250 KB | Re-optimize to N KB or Cap at N KB | Switches on Smart target file size if needed, then restores and re-optimizes those images to the target size. |
| N images come from outside your Media Library | none | Theme files and images hosted elsewhere can't be optimized. Replace them with Media Library images where you can. |
Fixes for images outside your Media Library aren't possible, and the report says so.
How fixes are applied
Fixes are applied to your pages as they're served. Your theme and content aren't modified, so switching a fix off undoes it. If you use a page cache, clear it after applying a fix so visitors get the change.
Page-specific fixes (Load it first, Serve the right size and the page's lazy-load list) are listed per page on the audit screen, with a Remove button. Up to 200 pages are kept for each kind of fix; when there are more, the oldest are dropped.
Automatic fixes
These apply to every page. Switch them on or off on the Page audit screen. All are off by default.
| Fix | What it does |
|---|---|
| Responsive sizes | Adds a srcset to Media Library images that lack one, with a sizes attribute based on the image's width (or 100vw), so phones download phone-sized files. |
| Missing width & height | Adds the real dimensions to Media Library images without them, so the browser reserves space and the page doesn't jump. A width or height you already set is kept, and the other one is worked out from the image's proportions. |
| Lazy-load offscreen images | Adds loading="lazy" and decoding="async" to every image after the first three on a page. Images that already have a loading attribute, or are marked high priority, are left alone. |
These work through the same page processing as picture-tag delivery. Feeds, embeds, AMP pages and the Customizer preview aren't changed.
Ultra compression level
A third card under Settings → Compression level: Maximum savings for speed-critical sites. PNGs become palette images.
| Ultra | |
|---|---|
| JPEG quality | 70, with 4:2:0 chroma subsampling |
| WebP quality | 70 |
| AVIF quality | 50 |
| PNG | Opaque PNGs are reduced to a 256-colour palette. PNGs with transparency stay full colour, because a palette can't keep soft edges. |
The PNG palette step needs Imagick. On GD, PNGs are compressed losslessly as on the other levels.
Smart target file size
Settings → Size & quality → Smart target file size, with a target from 50 to 1000 KB (default 250 KB) and presets of 100 KB · blogs & news, 200 KB · stores and 500 KB · photography.
When an image is optimized and its main file is still over the target, BytCrush re-encodes it, step by step, until it fits:
- quality is lowered by 10 at a time, down to 50;
- then the image is scaled down by 20% at a time, down to 800 px wide;
- then quality is lowered by 5 at a time, down to 40.
It stops as soon as the file fits, or at quality 40 and 800 px wide, whichever comes first. Very detailed photos can therefore end up slightly above the target.
- The target applies to the main file of JPEG and WebP images. PNGs and the sizes WordPress generates use the normal compression level.
- It applies when an image is optimized: new uploads, bulk runs and Re-optimize. To apply it to images that are already optimized, re-optimize them, or use the audit's Cap at N KB fix.
Licensing
BytCrush Pro is sold and licensed through Freemius.
Buy, or start the 14-day free trial (no card needed): from BytCrush → Go Pro, the PRO links in the plugin, or the Go Pro link on the Plugins screen.
Activate: after purchase, install the Pro zip from your Freemius email or account and enter your license key when asked. The header badge changes from Free to Pro and the Pro features unlock.
If a license lapses: optimizing, backups, WebP, AVIF and delivery keep working, because they're free. The Pro features stop:
- the page audit shows the locked teaser, and its automatic and page-specific fixes are no longer applied to your pages;
- a site set to Ultra uses Balanced for images optimized from then on;
- Smart target file size is switched off.
Images already optimized stay as they are. Your page-specific fixes are kept, and come back when you renew. Saving the Settings screen while the license is inactive stores the Pro options as off, so after renewing you may need to switch them on again.
Manage licenses, sites and invoices: in your Freemius customer account, or from Account in the plugin menu once the Freemius SDK is active.