WebP Converter

What is WebP?

WebP is a raster image format developed by Google for use on the web. It supports both lossy and lossless compression, and is supported by every modern major browser including Chrome, Firefox, Edge and Safari (since version 14, released in 2020). WebP is one of the image formats web.dev recommends for performance work, alongside AVIF.

This converter takes a single PNG, JPG or WebP image and writes out a WebP file at the original pixel dimensions. It is the simplest possible "convert to WebP" tool: upload, convert, download.

Why convert an image to WebP?

• Web images. WebP usually produces a smaller file than an equivalent PNG or JPG at comparable visual quality, which can speed up page loads and reduce bandwidth.
• Modern browser support. Chrome, Firefox, Edge, Safari and Opera all decode WebP natively, so a WebP file works as a drop-in replacement on a website or in a CMS.
• Re-encoding to a known quality band. A WebP file received from another tool can be brought back to a balanced quality setting without changing the dimensions.

WebP does not guarantee a smaller file for every source image. A small flat-colour icon may end up similar in size or slightly larger than the source PNG because WebP carries per-frame metadata. Compare the output to the original before deciding whether to keep it.

Quick Answer

The WebP Converter takes a single PNG, JPG or WebP image and outputs a WebP file at the same pixel dimensions as the source. It encodes at Pillow quality 85 — a balanced default for general-purpose web imagery — and does not resize, crop or upscale the input.

Requirements

Supported input

PNG, JPG, JPEG or WebP, up to 10 MB. SVG is not accepted because Pillow cannot faithfully rasterise it back into WebP.

Output format

A single .webp file named after the source. Pillow decides between lossy and lossless encoding based on the alpha channel.

Dimensions

Preserved exactly. A 1200 × 800 source becomes a 1200 × 800 WebP. No resize, no crop, no upscale.

How it works

1. 1 Upload. Choose a PNG, JPG or WebP file up to 10 MB.
2. 2 Convert. The workflow encodes the file as WebP at quality 85, keeping the original pixel dimensions.
3. 3 Download. Save the .webp file. Use it on a website, in a CMS, or anywhere modern browsers and image libraries read WebP.

Resize vs convert

Resize changes the pixel dimensions of an image — for example, fitting a 4000 by 3000 photo into a 1200 by 630 preview. Format conversion changes the file format while keeping the dimensions the same, so a 1200 by 630 PNG becomes a 1200 by 630 WebP. The two operations can both happen in the same workflow, but they solve different problems: resize is for fitting a target canvas, convert is for choosing a target file format. Use this WebP Converter when you only need to change the format and the source dimensions are already where you want them. Use the Social Media Image Resizer when you need a specific platform's pixel dimensions.

Common WebP mistakes

These are the issues that come up most often when converting an image to WebP. Each one is rooted in a property of the format or the encoder rather than in this specific tool.

• Assuming WebP is always smaller. WebP usually beats PNG and JPG at comparable quality, but a small flat-colour icon may end up similar in size or slightly larger than the source PNG because WebP carries per-frame metadata. Compare the output to the original before deciding whether to keep it.
• Treating a smaller file as automatically better quality. This converter uses quality 85 on the Pillow 0 to 100 scale, a balanced default. The right comparison is the actual visual result at the actual display size, not the byte count on disk. If the WebP shows block artefacts, ringing around edges, colour banding or text smearing, the source was already too aggressive for that quality band. A full checklist of those four symptoms and their fixes is on the over-compressed image guide.
• Converting an already-optimised image without checking the result. If the source was already a tightly compressed WebP, the re-encode may not improve file size at the default quality. Use the original if it is already small enough; convert only when the source format or quality band is not what you need.
• Choosing an unnecessarily low quality. This converter uses quality 85 on the Pillow 0 to 100 scale, a balanced default. Aggressive re-encoding at much lower quality is a manual job in another tool; this workflow ships one opinionated default so the output is predictable.
• Expecting WebP conversion to change image dimensions. The converter preserves the source dimensions exactly: a 1200 by 800 source becomes a 1200 by 800 WebP, with no resize, crop or upscale. If you need a different size, resize the source in a design tool or with another Beita Image workflow first.

Check the output

After the converter runs, verify these four things on the actual file before you ship it. The result panel shows the byte counts; the rest of this list is the validation pass a responsible WebP shipper runs once per output.

• Dimensions. Confirm the WebP's pixel dimensions still match the destination display slot. The converter never resizes, so the output width and height match the source — but the check matters because WebP conversion alone does not fix an image that is far larger than what the page renders. Chrome for Developers' Properly size images Lighthouse audit is the first-party reference for that case; if the source has more pixels than the layout uses, resize before converting, do not rely on WebP conversion to make up for it.
• File size. Confirm the WebP's bytes are at or below the destination's documented limit (a CMS upload cap, an email attachment cap, a page payload budget) and below the size you actually need. The result panel shows the measured original and WebP sizes for the file you uploaded, so the comparison is honest. WebP usually produces a smaller file than an equivalent PNG or JPEG at comparable visual quality, but a small flat-colour icon may end up similar in size or slightly larger because WebP carries per-frame metadata — that is also a property of the format, not a bug in this converter.
• Visual quality. Open the WebP at the actual display size and look for the four visible symptoms of over-compression: 8 by 8 pixel block patterns in flat colour regions, halos or ringing around sharp edges, visible colour bands in smooth gradients and smearing of small text or fine detail. Pillow's quality 85 on the 0 to 100 scale is the balanced default this converter uses; if any symptom is visible, the right move is to keep the original and convert in a tool that can sweep the quality, or to choose a different format entirely. A dedicated walkthrough of those four symptoms and their fixes lives on the over-compressed image guide.
• Real destination. Upload the WebP to the actual page, CMS, email or design tool where it will be used, and view it there. WebP is decoded by every modern major browser (Chrome, Firefox, Edge, Safari since version 14 in 2020) but not by every email client, print pipeline or older image tool. If the destination is anything other than a website with a modern browser audience, also keep a JPEG or PNG fallback — the Optimize Images for the Web guide covers the <picture> + <source> fallback pattern in detail, and it is the last check before the file is shipped.

WebP Converter vs Image Compressor

The two workflows answer different questions and they pair well rather than overlap. The WebP Converter changes the file format to WebP at the source's pixel dimensions and may also produce a smaller file as a side effect, depending on the source content and the WebP encoder settings. The Image Compressor reduces the file size of a PNG, JPG or WebP image while keeping the source format and the source dimensions. Use this WebP Converter when you want to ship WebP and the destination reads WebP. Use the Image Compressor when you need a smaller file in the same format as the source. Combining both — first compress in the source format, then convert to WebP — is also a reasonable pipeline if the source is large.

WebP does not always produce a smaller file than an equivalent PNG or JPG, especially for small flat-colour graphics where the per-frame metadata is a noticeable share of the total bytes. The two tools report measured sizes, not promised reductions; the right tool for a given file depends on what the destination reads and how the source compresses, not on which tool claims a larger reduction.

Sources

Each factual claim on this page — the WebP format itself, Pillow's encoder parameters, web.dev's recommendation, and the browser support picture — is sourced from the canonical documentation below.

• Google Developers - WebP image format: https://developers.google.com/speed/webp — WebP format overview, lossless/lossy compression, browser support.
• Pillow (PIL) documentation - Image.save WebP: https://pillow.readthedocs.io/en/stable/handbook/image-file-formats.html#webp — Pillow WebP encoder parameters, quality scale, lossless mode.
• web.dev - Serve images in modern formats: https://web.dev/articles/serve-images-webp — Why modern image formats (WebP, AVIF) are recommended for web performance.
• MDN - WebP image format: https://developer.mozilla.org/en-US/docs/Web/Media/Guides/Formats/Image_types#webp — Browser compatibility and format reference for WebP.