WebP to JPG: Fix the “Cannot Open” Error in Seconds

My mother called me asking why the recipe photos she saved from a website looked like broken file icons when she tried to open them on her laptop. They were WebP files — Chrome had saved them, but her Windows Photo Viewer from 2016 could not read the format. Converting them to JPEG took two minutes. Problem solved, recipes visible.

The WebP to JPG converter runs in a browser tab. No software to install, no files uploaded to a server.

Why WebP Causes Compatibility Problems

WebP was introduced by Google in 2010 and only gained widespread browser support in the early 2020s. The critical word is browser — WebP was designed for web delivery, not for the broader ecosystem of desktop applications, email clients, and professional tools. Any software not actively updated to add WebP codec support cannot open the format. That list is long: Windows Photo Viewer on systems not updated since 2018, Outlook and virtually every email client when previewing attachments, older versions of Photoshop and Lightroom (before the 2022 update), Apple Preview on macOS Mojave and earlier, most print services and photo portals, and many upload forms that only accept JPEG and PNG.

JPEG has had universal support across every operating system, application, email client, print workflow, and web platform for more than three decades. Converting WebP to JPEG makes an image that works everywhere with no exceptions.

Quality Setting: How to Choose

The quality slider (1–100) controls JPEG compression. Higher values keep more pixel data and produce larger files; lower values discard more data. A quality of 85 is the recommended default. It produces sharp images visually indistinguishable from the source at normal screen viewing sizes, with file sizes appropriate for email attachments, web uploads, and general sharing. For images that will be printed at large sizes or examined closely — product photography, real estate, portraits — use 90–95. For web thumbnails where file size matters more than absolute sharpness, 70–80 is adequate. Below 60, JPEG artefacts (blockiness around edges, banding in gradients) become visible at normal viewing sizes.

Resizing During Conversion

You can specify a target width or height before converting and the tool maintains the original aspect ratio automatically. Set both independently only if you want to stretch to specific dimensions. Use the resize option to produce JPEG output at exact pixel dimensions required by a platform specification, CMS image field, or email template without needing to open an image editor as a separate step.

JPEG and Transparency

JPEG does not support an alpha channel. If your source WebP file uses transparency — a logo with a transparent background, a cut-out product image, a UI element with partial opacity — converting to JPEG will fill transparent areas with a solid colour, typically white. If you need to preserve transparency, convert to PNG instead. PNG supports full alpha channel transparency and is universally supported by design tools and platforms that handle transparent images.

When JPEG Is the Right Choice

JPEG is correct when you want universal compatibility for a non-transparent image and file size matters. It is smaller than PNG for photographs and complex images, accepted everywhere, and supported by every email client, print service, and upload portal without exception. For graphics with flat colours, text, or transparency, PNG is technically superior. For photos and illustrations with gradients, JPEG at 85 or above gives you a universally compatible file at a reasonable size.

Frequently Asked Questions

Why can't my software open WebP files?

WebP requires specific codec support. Software not updated to include the WebP codec — older Windows image viewers, some email clients, older professional tools — does not recognise the format. JPEG is universally supported by everything. Converting to JPEG solves the compatibility problem permanently for that file.

Will there be quality loss when converting?

The quality slider controls JPEG compression. At 85 or above, the output is visually indistinguishable from the source at normal viewing sizes. JPEG is a lossy format, so very low quality settings produce visible artefacts. Use 85 or above for anything that will be viewed at full size or printed.

Are my images uploaded to a server?

No. All conversion happens locally in your browser. Your image data never leaves your device — no file is sent to any server at any point during the conversion.