SparkCore
Next-gen images without the developer matrix
AVIF, WebP and fallbacks: Spark chooses what works for each visitor.
In short
- Next-gen formats are WebP and AVIF: smaller than JPEG and PNG.
- Serve them per browser and keep JPEG or PNG as a fallback.
- Automate it, so your existing library is covered too.
One policy
Set compression and formats centrally in the plugin.
What are next-gen images in WordPress?
Next-gen is the name for modern image formats, mainly WebP and AVIF. They compress more efficiently than JPEG and PNG. At the same visible quality the files are smaller. All current major browsers support WebP. AVIF works in current versions of Chrome, Edge, Firefox and Safari. The images already in your library do not convert by themselves. For that you need a fixed workflow or a plugin.
What do next-gen formats deliver for PageSpeed?
Tools like PageSpeed Insights often point to modern formats as a gain. Smaller files mean less data and a faster LCP. A good LCP is 2.5 seconds or less. On mobile you notice the difference most. The gain depends on your page. A site full of photos gains more than a site that is mostly text. So measure before and after on the same page, with the same settings.
- Fewer bytes per image
- Faster LCP for large heroes
- Less data use on mobile
How do you serve WebP and AVIF with a fallback?
Not every visitor has the same browser. So you serve each visitor the best format that works. A browser that understands AVIF gets AVIF. Otherwise WebP follows, and otherwise JPEG or PNG. You can do this with the picture element or with server rules based on the Accept header. The order matters: the smallest first, the safest last. Test with an older browser to see if the fallback really works.
How do you automate next-gen images?
Exporting by hand takes time and is easily forgotten. A fixed policy that applies to every upload is better. Spark Media Optimizer does this in a background queue. You upload as usual and your dashboard stays usable. New uploads and your existing library go through the queue in bulk, including files from before installation. WebP and AVIF go to browsers that support them, with JPEG or PNG as a fallback.
- One policy for all uploads
- Existing library in bulk
- Originals are kept as a safe copy
Frequently asked questions
AVIF is often the smallest. WebP has wider and longer support. Combine them: AVIF where possible, WebP as a middle step and JPEG or PNG as a fallback. That way every visitor gets the smallest file their browser can handle.
Only if you compress too hard. Spark Media Optimizer picks, per image, the level that gives no visible difference on screen. Still check photos with a lot of fine detail by eye.
Yes. WebP supports transparency, just like PNG. For logos and graphics with sharp edges, PNG remains a safe fallback. Take a good look at the edges after conversion, especially for logos on coloured backgrounds.