Run your site through PageSpeed Insights. Chances are, somewhere in the results, you will see the line: “Serve images in next-gen formats.” It has probably been there for a while. You have probably ignored it.
That is fair. The suggestion sounds simple, but the actual work never felt safe. Most WebP plugins want to rewrite your URLs, replace your originals, or route your images through someone else’s server. Any of those can break things in ways that are hard to undo — a CDN stops serving the right file, an old embed points at nothing, a plugin you forgot about caches the wrong URL. So you leave the suggestion there and move on.
But the cost of ignoring it adds up. A JPEG from 2024 weighs 200–800 KB. A site with a hundred images is shipping tens of megabytes in a format from 1992. WebP cuts 25–35% off that weight with no visible quality loss, and every major browser has supported it for years. That is real bandwidth, real load time, and a real Core Web Vitals score sitting on the table.
ImageCraft handles the conversion without any of the risk. It creates a WebP copy beside each original — photo.jpg gets a photo.jpg.webp in the same folder. Your original files stay exactly where they are, named exactly what they are named, with exactly the same URLs. On your public pages, a standard <picture> element lets the browser pick the WebP when it can, and the original when it can’t. Turn it off, and every page goes back to how it was.
TL;DR
- ImageCraft generates WebP copies of your images and serves them to browsers that support the format. Originals are the automatic fallback.
- Your original files are never touched. The WebP copies sit beside them as sidecar files (
photo.jpg.webp). Remove them anytime, and you are back to where you started. - Setup: go to ImageCraft → Performance → Next-gen Formats, turn on WebP and Serve next-gen images, then convert images from the Compress screen.
- Delivery uses the HTML
<picture>element. The browser picks the format. No.htaccessrules, no server config, no rewrite tricks. - Typical savings: 25–35% smaller files, no visible quality loss.
- Free includes manual and bulk WebP conversion plus
<picture>delivery. Pro adds AVIF, auto-convert on upload, and no daily limit. - It is off by default. Updating the plugin changes nothing until you turn it on.
Why your images are bigger than they need to be
JPEG is from 1992. PNG is from 1996. Both do their jobs, but their compression is showing its age. A 400 KB JPEG becomes a 260–300 KB WebP. A 1.2 MB PNG with transparency can drop to 400–600 KB. Same picture, same quality, fewer bytes.
On a single blog post with six images, that saves 500 KB to 1 MB. On a WooCommerce category page with twenty thumbnails, you save several megabytes. Multiply that by your monthly traffic and you are talking about gigabytes of bandwidth — bandwidth your visitors are paying for with their time, and you might be paying for with your hosting bill.
Google cares. Core Web Vitals measure how fast your largest visible content loads — Largest Contentful Paint, or LCP. On most pages, that content is an image. Smaller image, faster LCP, better search ranking. Google has been saying this since 2021, and they are the ones who built WebP in the first place.
Browser support is not a concern anymore. Safari was the last holdout. It added WebP in 2022. As of mid-2026, over 97% of web traffic comes from browsers that handle WebP. The <picture> fallback covers the rest, so no visitor ever sees a broken image.
How other plugins do it (and why you hesitated)
If you have looked into WebP before, you probably ran into one of these approaches and thought “maybe later.”
Cloud services send your images to someone else’s server, convert them there, and serve them back — sometimes from a CDN, sometimes as a replacement in your uploads folder. The conversion is fast, but your images pass through a third party. You pay per image or per month. And if that service disappears or has a bad day, your images are part of the problem.
Rewrite plugins generate WebP files on your server, then use .htaccess or Nginx rules to swap the file the browser actually receives. When your server setup is standard, this works. When it is not — a reverse proxy, a CDN that ignores rewrite rules, a managed host with locked config — the swap silently fails. Your visitor gets the old JPEG, you think they are getting WebP, and nobody knows until you wonder why your scores haven’t changed.
Replace-in-place plugins convert your originals directly. The JPEG becomes a WebP. This is efficient, but it is also permanent. If another plugin, a theme, or a CDN still expects the old file at the old URL, things break. And if you want to go back, you need a backup — if you made one.
Each of these works for some people. But each asks you to trust something: a third party, a server config, or the idea that you will never want the original back. That trust is why a lot of people never flip the switch.
How ImageCraft does it differently
ImageCraft does not replace anything, rewrite anything, or send anything to an external server.
Sidecar files
When you convert an image, ImageCraft reads the original and writes a WebP version next to it. If the original is wp-content/uploads/2025/06/photo.jpg, the WebP is wp-content/uploads/2025/06/photo.jpg.webp. Same folder. Predictable name. It does this for the full-size image and for every size WordPress generated — thumbnails, medium, large, all of them.
Your original file is not renamed. Not moved. Not deleted. Not re-encoded. The Media Library entry does not change. The URL does not change. Open your uploads folder and you see the same files as before, plus the .webp files sitting beside them.
<picture> delivery
On your public pages, ImageCraft wraps each <img> in a <picture> element:
<!-- What your page normally outputs -->
<img src="photo.jpg" alt="A sunrise over the mountains">
<!-- What ImageCraft turns it into -->
<picture>
<source type="image/webp" srcset="photo.jpg.webp">
<img src="photo.jpg" alt="A sunrise over the mountains">
</picture>The browser reads this top to bottom. If it knows WebP, it grabs the <source>. If it doesn’t, it grabs the <img>. That is how the <picture> element was designed to work — standard HTML, not a hack. No JavaScript. No server-side browser sniffing. No .htaccess. It works behind any CDN, with any caching plugin, on any host.
Never-bigger guard
WebP does not always win. A tiny PNG or an already-optimized file can sometimes produce a WebP that is actually larger. ImageCraft checks: if the WebP is not smaller than the original, it throws it away and moves on. You never serve a file that is worse than what you had.
One-click cleanup
Every conversion is tracked in the image’s metadata. If you ever want to remove all the WebP files — all of them, at once — there is a Clean button. It removes the sidecar files and the metadata. Your originals, again, are not touched.
Setup: turn it on, convert your library
You do this once.
- Install or update ImageCraft from the WordPress plugin directory.
- Go to ImageCraft → Performance → Next-gen Formats.
- Turn on WebP. This tells ImageCraft you want to create WebP copies. It does not convert anything yet.
- Turn on Serve next-gen images. This enables the
<picture>delivery on your public pages. - Click save.
That is it. Now you can start converting.
If the toggle says “Not supported by server”: your host does not have the PHP extensions needed to create WebP files (Imagick with WebP support, or GD with
imagewebp). Most modern WordPress hosts have this out of the box. If yours does not, contact them — it is usually a one-line configuration change on their side.
Converting images to WebP
From the Compress screen. Go to ImageCraft → Performance. Your images are listed with sizes and status. Select the ones you want and click Convert Selected. ImageCraft creates the WebP sidecar for each image and its sizes. Everything runs on your server. No files go anywhere.
From the media modal. Open any image in the WordPress media modal — from the Media Library or from inside a post. The ImageCraft panel has a Convert button alongside Compress and Rename. One click, one image, done.
Both paths do the same thing. The Compress screen is better for working through a backlog. The media modal is better when you are looking at a specific image right now.
How your visitors get the smaller files
Once an image has a WebP sidecar and delivery is on, there is nothing else to do. ImageCraft wraps each matching <img> in a <picture> element. The browser picks the smaller file. The original is always there as a fallback.
- Only converted images get wrapped. If you have 500 images and you converted 200 of them, only those 200 get the
<picture>treatment. The other 300 show up exactly as before. - It does not run in wp-admin. Your editor, your Media Library, your admin screens all show the originals. The WebP swap is for visitors only.
- Caching plugins just work. The
<picture>HTML caches like any other markup. WP Super Cache, W3 Total Cache, LiteSpeed, WP Rocket — no special config. - CDNs just work. The browser decides the format, not the server. No CDN-side rules needed.
Bulk convert: do the whole library at once
One at a time is fine for a handful of photos. If you have hundreds, you want the bulk route.
- Go to ImageCraft → Performance (the Compress screen).
- A scan shows how many images can be converted and how many already have been.
- Select what you want, or hit Select All.
- Click Convert Selected.
The batch runs in the background with a progress bar. You can close the browser and come back later — the job keeps going. Images already converted are skipped. Images where the WebP would be larger are skipped too.
How long does it take? Depends on your server and the number of images. On a typical shared host, roughly 1–3 seconds per image. A 500-image library takes maybe 10–25 minutes. You are only doing this once.
Tip: If you already compressed your images with ImageCraft, the WebP conversion works from the compressed files. Compression reduces the image data — strips metadata, optimizes encoding. WebP uses a more efficient format on top of that. The savings stack.
Will this slow down my site?
The opposite. Your pages will load faster. The conversion is a one-time job. Once a WebP sidecar exists, it is just a file on disk. Serving it adds nothing to your page load — the <picture> wrapper is built once when WordPress renders the page, and after that it is static HTML.
The files themselves are smaller, so every image loads faster. Pages with lots of images — blog archives, product category pages, portfolio grids — see the biggest difference, because the savings stack across every image in the layout.
What about AVIF?
AVIF goes further than WebP. It usually produces files 20–30% smaller than WebP, which means 40–50% smaller than the original JPEG. Chrome, Firefox, and Safari all support it now, though not as universally as WebP yet.
ImageCraft handles AVIF the same way — sidecar files, <picture> delivery, never-bigger guard, one-click cleanup. The <picture> element offers AVIF first, then WebP, then the original. The browser picks the best it can handle.
The catch is on the server side. AVIF encoding needs either PHP 8.1+ with GD’s imageavif(), or Imagick with an AVIF delegate. A lot of WordPress hosts do not have this yet. If yours does not, ImageCraft says “Not supported by server” on the AVIF toggle — no guessing, no cryptic error.
AVIF is a Pro feature. If your server supports it, Pro unlocks the toggle.
Free vs Pro
| Free | Pro | |
|---|---|---|
| WebP conversion | Manual single + bulk | Manual + auto on upload |
| WebP delivery | Yes | Yes |
| AVIF | — | Yes (where server supports it) |
| Daily limit | 50 actions / 24 hours (shared with compression and alt text) | Unlimited |
| Auto-convert on upload | — | Yes |
Frequently asked questions
Does this change my original images?
No. Your originals are never modified, renamed, or deleted. The WebP files are separate copies sitting next to them. Turn the feature off and your pages serve the originals as if nothing happened.
What if I turn off delivery?
The <picture> wrappers disappear from your pages. Every <img> renders as it did before. The WebP files stay on disk but nothing uses them.
Can I remove all the WebP files at once?
Yes. The Clean button removes every sidecar file and its tracking metadata. Your originals stay.
Does it work with my CDN?
Yes. The browser picks the format using the <picture> element — the server and CDN are not involved in that decision. No CDN configuration needed.
Does it work with caching plugins?
Yes. The <picture> HTML is page-level markup, cached like everything else. No special setup.
Will old browsers see broken images?
No. A browser that does not understand <picture> ignores it and loads the <img> inside. A browser that understands <picture> but not WebP skips the <source> and loads the <img>. Either way, the visitor sees an image.
Is the conversion done locally?
Yes. Everything runs on your WordPress server using PHP’s image libraries — Imagick or GD. Nothing is sent to an external service.
How much disk space do the WebP files use?
Less than the originals they were made from. Worst case, your uploads folder grows by roughly 65–75% of the originals’ combined size. For most sites that is a few hundred MB.
I already compressed my images. Should I also do WebP?
Yes. They work together. Compression reduces the image data. WebP uses a more efficient format to encode it. You get both savings stacked.
Does this help my SEO?
Yes. Smaller images load faster, which improves Largest Contentful Paint — a direct Google ranking signal. Your alt text, dimensions, and other image attributes are unaffected.
Do I need an API key for this?
No. WebP conversion has nothing to do with the AI features. You can use ImageCraft purely for WebP without ever adding a key.
I updated the plugin — did anything change on my site?
No. Next-gen Formats is off by default. Nothing changes until you turn it on.
Get started
You have probably seen “Serve images in next-gen formats” on your PageSpeed report more than once. The reason it stays there, for most sites, is not that WebP is complicated. It is that the path to get there felt like it might break something.
ImageCraft takes the risk out of it. Your originals never move. WebP copies sit beside them, and a standard <picture> element lets the browser pick the smaller file. No URL changes, no server rules, no third-party service. Turn it off and your site is exactly what it was before.
Open ImageCraft → Performance → Next-gen Formats, turn on WebP and Serve next-gen images, save, then go to the Compress screen and bulk-convert your library. Five minutes, and every image on your site gets lighter without a single original being touched.
Ready to serve smaller, faster images? Get ImageCraft →
