WordPress 5.3 and Large Image Uploads

What arrived today

WordPress 5.3 was released today. For most business sites, the change worth understanding is how it handles very large photographs.

Any image uploaded from now on that is more than 2,560 pixels wide or tall gets a scaled-down copy, and that copy becomes the largest version the site uses.

The release also brings a new default theme, Twenty Twenty, improvements to the block editor, and a periodic check that the site's administration email address is still right.

Most of it is invisible to visitors. All of it is worth testing before the live site updates.

What the change does

• A threshold of 2,560 pixels on an image's longer side.
• A scaled copy, made on upload, with scaled added to its file name.
• That copy becomes full size wherever the site offers full size.
• The original stays on the server, untouched.
• Only new uploads are affected; the existing library is left alone.
• A developer can change the limit, or switch it off.

The fourth is the one most often misread. Visitors are served smaller images, but the server keeps every original, so storage and backups grow at least as fast as before.

Why camera photographs were a problem

A recent phone takes photographs around 4,000 pixels wide, and a good camera often 6,000. Straight off the card, each can be several megabytes.

WordPress has always made smaller copies for thumbnails and page content, which is why most pages were fine.

The trouble was wherever the site used full size: galleries that open a photograph when tapped, images inserted at full size in the editor, and some themes' banners. There, a visitor on a phone downloaded the original.

What changes for staff who upload from a camera

Once a site is on 5.3, those same places serve the 2,560-pixel copy of each new upload instead. That is still enough for a large desktop monitor, at a fraction of the original's weight.

Staff do not need to change how they upload for that to happen. The scaling is automatic.

The upload itself does not change. A ten-megabyte photograph still travels to the server in full, and very large uploads still fail more often on a slow connection or a busy shared plan.

Resizing before upload, with an export setting in the camera's or phone's software, remains the better habit. The new limit is a safety net, not a replacement.

Twenty Twenty and the rest of the release

Twenty Twenty is the default theme for new installations. An existing site keeps its current theme through the update, and nothing switches on its own.

The block editor gets a round of improvements. Sites built with the Classic Editor plugin or a page builder will notice less, but pages built with blocks should be checked on a copy.

And every six months, WordPress will now ask an administrator who logs in to confirm that the administration email address is still correct.

That is the address that receives the recovery link when a plugin crashes the site, so answer the question properly rather than clicking past it.

A worked example

A used boat dealer with a lot beside the highway keeps thirty or forty boats listed at a time, each with fifteen or twenty photographs taken by the sales staff on a good camera.

The photographs go into WordPress straight off the memory card, about 6,000 pixels wide and several megabytes each.

The listing pages use the theme's large size and load reasonably. But tapping a photograph opens it at full size, so a buyer flicking through one boat's gallery on a phone downloads every original.

Under 5.3, new uploads will open at 2,560 pixels instead. Older listings will keep opening their originals, but boats sell, and the problem leaves with them.

The dealer's web company is updating a copy of the site first, to check that the gallery plugin picks up the scaled files and the boat search still works.

Staff are also adding an export size to the camera software, because the hosting space was filling with originals, and 5.3 still keeps every one.

Testing on a copy first

Minor security releases install themselves, but a major release such as 5.3 waits for somebody to apply it, unless the host or a maintenance plan does that automatically.

Take a backup, update a copy of the site, and upload one photograph straight from a camera or phone. Check that the scaled copy appears in the media library and that pages use it.

Then open every gallery, slider and lightbox on a phone. Those are the places that used full size, and the places an older plugin could behave unexpectedly.

Image plugins that already resize

Many sites already run a plugin that shrinks or compresses uploads. After the update, two pieces of software may be making decisions about the same file.

Check the plugin's settings on the test copy and decide which of the two sets the size limit, so uploads are not processed twice under different rules.

When you need the original

A few sites genuinely need full-resolution images: a photographer selling prints, a manufacturer offering print-ready product shots to retailers, a portfolio meant for very large screens.

For them, a scaled copy standing in for full size is a step backwards. A developer can raise the limit or switch it off, and the originals remain on the server either way.

Decide before updating, not after a customer asks why a download looks smaller.

The counter-case

A site whose images are already resized before upload will see no difference. Neither will one that rarely adds photographs.

The change also does nothing for images already in the library, or for storage, which keeps filling at the same rate.

For a site where staff upload straight from a camera, though, 5.3 is a quiet improvement worth having, once it has been tested on a copy.

Before you update

1. Take a full backup of files and database.
2. Update a copy first, not the live site.
3. Upload one camera photograph and check its sizes.
4. Open every gallery and lightbox on a phone.
5. Check your image plugin's resize settings.
6. Ask who needs full originals, if anybody.
7. Confirm the admin email when WordPress asks.

Step four is where any problem will show. Galleries and lightboxes were the places using full-size images, so they are where the change is visible, for better or, with an older plugin, for worse.

The previous major release is covered in WordPress 5.2 and the Site Health screen.

Frequently asked questions

West Coast Media Solutions Inc. provides web design, web development, hosting, digital marketing, and business consulting to organisations across Canada, drawing on more than twenty-five years in the field.