PNG vs JPG vs WebP: Which Image Format Should You Use?

Use JPG for photographs, PNG when you need transparency or crisp text and lines, and WebP when you want smaller files and your audience is on modern browsers. Almost every real decision comes down to two questions: does the image have a transparent background, and is it a photo or a graphic?

JPG (also written JPEG) uses lossy compression. It throws away image data your eye is unlikely to notice, which makes photo files dramatically smaller than the raw pixels would be. For a beach photo or a portrait with smooth gradients and thousands of colors, this is exactly what you want, and the quality loss is usually invisible.

JPG has two real weaknesses. First, it has no alpha channel, so every pixel is opaque and there is no transparency. Second, it handles sharp edges badly: put black text or a hard line on a solid background and JPG adds fuzzy, blocky halos around the edges, called compression artifacts. That is why a screenshot of a document saved as JPG looks smudged while the same screenshot as PNG stays razor sharp.

PNG uses lossless compression. It reduces file size without discarding any pixel data, so what you put in is exactly what you get out. That makes it perfect for logos, icons, screenshots, diagrams, and anything with text or sharp edges, with none of the fuzzy artifacts JPG produces.

PNG's headline feature is a full alpha channel: pixels can be fully transparent, fully opaque, or anything in between. That is how a logo sits cleanly on any background color. The trade-off is size. For a full-color photograph, a PNG is often several times larger than the equivalent JPG, because lossless compression simply cannot shrink a noisy photo as much. Reach for PNG when you need transparency or pixel-perfect edges, not for holiday snaps.

WebP is Google's newer format, and it supports both a lossy mode (like JPG) and transparency (like PNG), typically at a smaller file size than either. A WebP photo is usually noticeably smaller than the same-quality JPG, and a WebP graphic with transparency is usually smaller than the PNG. That is why so many websites now serve WebP.

The catch is compatibility. WebP works in every current major browser, but very old browsers and some older desktop apps, email clients, and image editors still choke on it. If you are publishing to a modern website, WebP is a great default. If you are emailing a file to a client or handing it to someone on unknown software, JPG or PNG is the safer bet. There is also AVIF, an even newer format that compresses better still, but its encoding support is patchier, so treat it as a bonus rather than a default.

Trap one: converting PNG to JPG destroys transparency. JPG has no alpha channel, so every transparent pixel has to become something opaque. Tools fill those transparent areas with a solid color, and white is the usual choice. FileTinker's converter does exactly this: when you convert to JPG (or to GIF or BMP), any transparent areas are flattened onto a white background. If your logo had transparent corners, they come out white. This is not a bug, it is unavoidable with JPG. To keep transparency, convert to PNG or WebP instead.

Trap two: re-saving a JPG over and over degrades it. Because JPG is lossy, every save throws away a little more data. Open a JPG, make a small edit, save as JPG, and repeat a few times, and you get visible generation loss, the copy-of-a-copy effect. Colors get muddier and artifacts pile up. The same applies to lossy WebP. The fix is to keep your master copy in a lossless format (PNG, or the original camera file) and export to JPG or WebP only once, at the end.

FileTinker's Image Converter and Compress Image tools run entirely in your browser, so nothing is uploaded, but it is worth knowing what they do to your pixels so you are not surprised.

The converter decodes your image, draws it to a canvas, and re-encodes it in the target format. PNG output is lossless, so a conversion to PNG keeps every pixel exactly. But JPG, WebP, and AVIF output are encoded at a fixed quality of about 0.92, which is lossy. That means converting a photo to JPG or WebP is a re-encode, not a perfect copy, and re-saving repeatedly still accumulates loss. This is normal for those formats, and 0.92 is a high-quality setting, but it is not magic: there is no lossless JPG or lossless WebP conversion here. AVIF is only offered when your browser can encode it (Chrome and Edge today, not Firefox), so it shows up as an option rather than a guarantee.

The Compress Image tool keeps your source format when the browser can re-encode it (JPG, PNG, or WebP) and falls back to JPG for anything else. It also refuses to hand back a file that is not actually smaller: if re-encoding cannot beat the original bytes, it keeps your original untouched rather than pass off a larger file as a smaller one.

When you are staring at a Save As dialog, run through this in order: