JPG to WebP

About this converter

This free JPG to WebP converter turns a JPG into a modern WebP, which is typically 25–35% smaller at the same visual quality. The usual reason to do it is page speed: images are the heaviest thing on most web pages, and this is the cheapest way to make them lighter.

Everything runs in your browser — your image is never uploaded to a server.

Why WebP is smaller than JPG

JPEG was finalised in 1992. WebP arrived from Google in 2010, built on the compression work behind the VP8 video codec, and it has eighteen years of research that JPEG does not.

Two things account for most of the difference. WebP predicts each block from the pixels already decoded around it, so it stores only the error in that prediction rather than the block itself — a technique borrowed from video encoding, where consecutive frames are mostly the same. And it uses arithmetic coding, which packs the result more tightly than the Huffman coding JPEG relies on.

The practical result on photographs is a 25–35% saving at matched quality. On a page carrying two megabytes of JPEGs, that is roughly half a megabyte gone for no visible change.

What that does for page speed

Images are usually the largest thing a page downloads, which puts them directly in the path of the metric Google actually measures.

Largest Contentful Paint is how long the biggest visible element takes to appear — and on most pages that element is an image. It is one of the Core Web Vitals, it is a ranking signal, and it is dominated by how many bytes your hero image weighs. Cutting a third off it moves LCP directly.

This matters most for the people on the worst connections. On a fast desktop connection, 500 KB is imperceptible. On a congested mobile network it is a second of staring at nothing, and that second is where visitors leave.

Choosing a quality setting

WebP quality runs 0–100, and the number does not mean the same thing as a JPEG quality number. Some rough guidance:

• 80–85 — the sweet spot for photographs on the web. Differences from the original are essentially invisible at normal viewing size.
• 90+ — for images that will be zoomed, cropped later, or contain fine text. Files grow quickly above 90 for very little visible gain.
• 70–80 — thumbnails, background images, anything small or partly obscured.
• Below 70 — visible on photographs. Usable for a heavily blurred background, not much else.

If you are unsure, start at 82 and look at the result at full size. The places artefacts appear first are smooth gradients — skies, studio backdrops, skin — not busy detail.

Converting a JPG loses a little, unavoidably

Worth understanding before you convert a folder of originals.

A JPG is already lossy. Detail was discarded when it was first saved. Converting it to WebP decodes that compressed image and compresses it again with a different algorithm, so a second, smaller round of loss is added on top. This is generation loss, and it accumulates every time an image passes through a lossy format.

In practice one conversion at quality 80–85 is not visible. But it means two things:

Keep your originals. Convert copies for the web and keep the source files somewhere else. You cannot get the discarded detail back.

Do not convert repeatedly. JPG to WebP to JPG to WebP will visibly degrade. Always go back to the original rather than re-converting a converted file.

If you still have the untouched camera file or a PNG export, converting *that* to WebP gives a better result than converting the JPG.

Browser support, and the one exception

WebP is supported everywhere that matters. Chrome, Edge, Firefox, Opera and Samsung Internet have handled it for years, and Safari added it in version 14 (2020), which was the last real holdout. On the web you can serve WebP without a fallback today.

The exception is software, not browsers. Plenty of desktop and mobile applications still cannot open a .webp file: older versions of Photoshop, many print workflows, some Office installations, various photo frames and TVs, and a surprising number of upload forms that accept only JPG and PNG. That is the usual reason people need to convert the other way.

How to use it

• Upload your JPG — click the upload area or drag and drop a .jpg file
• Choose the quality — higher keeps more detail; lower makes a smaller file
• Download — save your WebP

Good to know

• Keep the original JPG. Conversion is one-way in terms of quality.
• Check the size actually dropped. On a small or already heavily compressed JPG, WebP occasionally comes out slightly larger. If it does, keep the JPG.
• Resize before converting. Serving a 4000-pixel image into a 800-pixel slot wastes far more bytes than any codec choice can recover.
• Some upload forms reject .webp. Job sites, government portals and older e-commerce back-ends often accept only JPG and PNG.
• WebP supports transparency, unlike JPG — so if you later convert a transparent WebP back to JPG, you will need to choose a background colour.
• AVIF is smaller still, roughly 20% below WebP, but encodes far more slowly and has slightly narrower support.

Common questions

How much smaller will my WebP be?

Usually 25–35% smaller than the JPG at the same visual quality, though it varies with the image. Photographs with smooth areas — skies, portraits, studio backgrounds — compress best. A small JPG that was already saved at low quality may shrink very little, and occasionally comes out slightly larger, in which case simply keep the JPG.

Does converting JPG to WebP reduce the quality?

Slightly, and unavoidably. The JPG already discarded detail when it was made, and re-encoding to WebP adds a second small round of loss. At quality 80–85 this is not visible at normal viewing size. Keep your original files and convert copies, because the discarded detail cannot be recovered.

Is WebP good for SEO?

Indirectly, and meaningfully. Google does not rank a format, but it does measure Largest Contentful Paint as a Core Web Vitals signal, and on most pages the largest element is an image. Cutting a third off your image bytes improves that metric directly, which is one of the few SEO changes with an immediate, measurable effect.

Do all browsers support WebP?

Yes, for practical purposes. Chrome, Firefox, Edge, Opera and Samsung Internet have supported it for years, and Safari added it in version 14 in 2020. The remaining gaps are in desktop and mobile applications rather than browsers — older Photoshop versions, print workflows and many upload forms still will not accept a .webp file.

What quality setting should I use?

Start at 82 for photographs. Use 90 or above for images containing fine text or that will be zoomed, and 70–80 for thumbnails and background images. Below 70 the artefacts become visible on real photographs, first in smooth gradients like skies rather than in busy detail.

Should I use WebP or AVIF?

WebP for most work. AVIF produces files around 20% smaller again, but it encodes much more slowly, support in software outside browsers is thinner, and the extra saving is small compared with the jump from JPG. WebP is the safe default; AVIF is worth it for a handful of very large hero images.

Is my image uploaded to your server?

No. The conversion runs entirely in your browser using its built-in image encoder, so your photograph never leaves your device. You can disconnect from the internet and the tool still works.

Related tools

• WebP to JPG — the other direction, for software that cannot open WebP
• PNG to WebP — for logos, screenshots and images with transparency
• Image Compressor — compress without changing format
• Image Resizer — resize first; it saves more bytes than any codec