The one-line version
Use JPG for photos, PNG for anything needing transparency or sharp text and lines, and WebP when you want the smallest file and don't specifically need one of the other two's particular strengths — WebP handles both photo-style and graphic-style content well and typically produces a smaller file than either at comparable visual quality. That single rule covers the large majority of everyday cases; the sections below cover the specific reasons behind it.
Convert between formats
JPG: built for photographs
JPG uses lossy compression, discarding some image detail — mostly in ways the human eye is least likely to notice — in exchange for a much smaller file than an uncompressed original. That trade-off works well for photographs, where gradual color transitions and natural detail hide compression artifacts reasonably well, but it shows up as visible fuzziness around sharp edges, which is exactly why JPG is a poor fit for text, logos, or line art. JPG also doesn't support transparency at all — any transparent area in a source image gets filled with a solid background color when saved as JPG.
PNG: built for sharp edges and transparency
PNG is lossless — it compresses without discarding any image data, so text, icons, screenshots, and graphics with hard edges stay perfectly crisp no matter how many times the file is re-saved. It's also the standard format for anything needing a transparent background, like a logo meant to sit on top of different colored surfaces. The trade-off is file size: a lossless format simply can't compress as aggressively as a lossy one, so a photo saved as PNG is typically several times larger than the same photo saved as JPG, for a difference in visual quality that's often not even noticeable.
WebP: modern, and usually smaller than both
WebP is a newer format built specifically to beat JPG and PNG at their own jobs — it supports both lossy compression (competing with JPG, typically producing files 25–35% smaller at similar visual quality) and lossless compression with full transparency support (competing with PNG, typically smaller too). Browser support is effectively universal across modern browsers as of 2026, which removed the main historical reason to avoid it. It's a strong default for web images specifically, where smaller files translate directly into faster page loads.
Why WebP isn't automatically the right choice everywhere
Despite its advantages for the web specifically, WebP isn't a universal replacement for JPG and PNG in every context. Some older software, certain print workflows, and a handful of platforms and content management systems still expect a JPG or PNG upload specifically and don't handle WebP smoothly, or at all. If an image needs to be edited further in another tool, printed through a workflow that expects a traditional format, or uploaded somewhere with an explicit format requirement, sticking with JPG or PNG for that specific step — and converting to WebP only for the final web-facing version — avoids friction down the line.
A quick decision guide
Ask two questions: does the image need a transparent background, and is it mostly a photograph or mostly graphics/text? A photo with no transparency need, headed to the web, is the clearest case for WebP or JPG. Anything needing transparency, or dominated by sharp text and lines, points to PNG (or WebP's lossless mode, where supported). When in doubt and the destination is a modern website, WebP is the safest general-purpose default in 2026.