Convert hundreds of images at once, in both directions, straight inside your browser. No upload, no server, no waiting — and a built-in file size controller that hits your target KB.
No images added yet — drop some files above to get started.
Privacy first: every conversion happens locally on your device using the HTML5 Canvas API. Your images are never uploaded, stored, or seen by anyone — not even us.
If you have ever tried to upload a folder of photos to a website, an online store, or a blog and watched the upload bar crawl, you already know the problem. Images are usually the heaviest thing on a page. A single unoptimised photo can weigh more than an entire article, and when you multiply that by a product catalogue, a photography portfolio, or a client gallery, you end up with a slow site that punishes both your visitors and your search rankings.
WebP was created to fix exactly that. It is a modern image format developed by Google that delivers the same visual quality as JPEG or PNG at a fraction of the file size. But here is the catch: switching formats is easy when you have one image and painful when you have four hundred. Most converters online handle one file at a time, watermark your output, cap your batch size, or quietly upload your pictures to a server you know nothing about.
This tool was built to remove all of those problems. It is a bulk WebP converter that works in both directions — you can push hundreds of JPG, PNG, AVIF, BMP, GIF, TIFF or SVG files into WebP, or pull WebP files back out into any popular format. Everything runs inside your browser tab. Nothing is uploaded. Nothing is logged. And because speed without control is useless, there is a dedicated file size controller that lets you say "make every image under 150 KB" and actually get that result.
Tip: For web use, a quality setting between 75 and 85 is the sweet spot. Most people cannot see the difference, but the file size drops dramatically compared to the original.
Convert hundreds of images to WebP at once, or convert WebP back into JPG, PNG, AVIF, BMP and ICO — all from the same interface.
Set an exact KB target and the engine binary-searches quality levels and dimensions until your image fits. No guesswork.
Processing happens in your browser with the Canvas API. Your files never leave your device — perfect for confidential or client work.
Download the whole batch as a single archive. No need to click through forty separate save dialogs.
Cap width, cap height, or scale by percentage. Aspect ratio is preserved automatically so nothing gets stretched.
Re-encoding through canvas removes hidden EXIF data, GPS coordinates and camera info — an extra layer of privacy for free.
See original size, new size and the exact percentage saved for every single image, plus totals for the whole batch.
Desktop, laptop, tablet, phone. No installation, no extension, no account, no sign-up, no limits.
There is no mystery server behind this tool. The entire pipeline runs on your own hardware, using APIs that every modern browser already ships with.
When you drop a file in, the browser decodes it into raw pixels using createImageBitmap() or a standard <img> element. This is the same decoder your browser uses to display any picture, which is why the tool accepts so many input formats — WebP, JPG, PNG, GIF, BMP, ICO, AVIF, TIFF, SVG and more, depending on what your browser can read.
The decoded image is drawn onto an off-screen <canvas>. If you set a maximum width, height or scale, the canvas is sized accordingly and the image is resampled with high-quality smoothing. Aspect ratio is calculated mathematically so nothing is ever distorted.
The canvas is encoded with canvas.toBlob() using your chosen MIME type and quality value. WebP, JPEG, PNG and AVIF use the browser's native encoder. BMP and ICO are generated by a small built-in encoder that writes the file headers and pixel data byte by byte — no libraries, no dependencies.
This is the part that makes the tool genuinely useful. When you set a target size, the engine does not just pick a random quality. It performs a binary search:
The result: you ask for "under 150 KB" and you get the best-looking 150 KB image the format can produce.
Converted blobs are held in memory. When you click Download ZIP, a ZIP archive is assembled directly in JavaScript — complete with CRC-32 checksums and proper headers — so it opens correctly in Windows Explorer, macOS Finder, and every extraction tool. Nothing ever touches a network.
WebP is not just "another format". It solves several problems at once, which is why it is now supported by every major browser.
| Feature | WebP | JPEG | PNG | GIF |
|---|---|---|---|---|
| Lossy compression | ✅ Yes | ✅ Yes | ❌ No | ❌ No |
| Lossless compression | ✅ Yes | ❌ No | ✅ Yes | ❌ No |
| Transparency (alpha) | ✅ Yes | ❌ No | ✅ Yes | Partial |
| Animation | ✅ Yes | ❌ No | ❌ No | ✅ Yes |
| Typical size vs JPEG | 25–35% smaller | Baseline | — | — |
| Typical size vs PNG | Up to 80% smaller | — | Baseline | — |
WebP's compression is simply more efficient. Independent tests consistently show 25–35% savings over JPEG at matched visual quality, and dramatically more against PNG — sometimes up to 80% smaller for the same image.
WebP handles photographs, logos, screenshots, transparent graphics and even animations. That means you can stop juggling JPEG for photos and PNG for transparency — one format covers it all.
Google uses page experience signals including Largest Contentful Paint, and images are usually the largest element on a page. Cutting image weight directly improves loading speed, bounce rate and search visibility.
If you pay for hosting, CDN traffic, or mobile data, smaller images mean smaller bills. For high-traffic sites the savings compound fast.
Chrome, Edge, Firefox, Opera, Safari and every modern mobile browser read WebP natively. There is no compatibility excuse left.
Image optimisation should not be a chore, and it definitely should not cost you your privacy. This bulk WebP converter gives you the two things that actually matter: speed and control. Speed, because you can process an entire folder in one pass instead of dragging files into a converter one at a time. Control, because the size controller lets you dictate the exact result you need rather than hoping for the best.
Whether you are converting a thousand product photos into WebP to speed up an online store, or pulling WebP files back into PNG because an old client system refuses to open them, the workflow is the same: drop, choose, convert, download. No account, no upload, no watermark, no file limit.
Bookmark this page, and the next time your site starts feeling heavy, you will know exactly where to start.
Scroll back up, drop your files, and watch the size drop.