JPG, PNG or WebP: Which Image Format to Use When

JPG: built for photographs, allergic to edges

JPEG compression exploits how eyes see the world: smooth gradients and busy textures hide small errors well, so photographic detail compresses spectacularly. A holiday photo at quality 80 keeps a tenth of its original bytes with no visible difference at normal viewing.

Its weakness is the hard edge. Text, line art and flat-color areas develop the famous mosquito noise: faint ripples hugging every sharp boundary. A screenshot saved as JPG looks smudged for exactly this reason. JPG also has no transparency; any see-through area becomes solid white or black.

One trap deserves bold letters: JPG loses quality EVERY time it is saved, not just the first. Edit, save, edit, save, and artifacts stack like photocopies of photocopies. Keep an original, export a JPG at the end, and never chain edits through repeated JPG saves.

PNG: pixel-perfect, transparency, and honest about the cost

PNG is lossless: every pixel survives exactly, forever, no matter how many times the file is opened and saved. That makes it the home format for screenshots, UI graphics, diagrams, logos and anything with text in it; edges stay razor sharp because nothing was approximated.

It also carries a real alpha channel, so transparency works properly: soft shadows, anti-aliased edges and glass effects all composite cleanly onto any background. This is why 'logo with transparent background' means PNG in practice.

The cost is size on the wrong content. A photograph saved as PNG can weigh five to ten times its JPG equivalent for no visible benefit, because photographic noise is incompressible without loss. PNG for photos is the single most common format mistake on the web.

WebP: one format that plays both games

WebP does lossy compression like JPG but roughly 25-30% smaller at the same visual quality, and lossless compression like PNG, usually a quarter smaller, WITH transparency in both modes. For anything living on a website, it is generally the right answer today.

Its historic weakness, compatibility, is largely over: every current browser renders WebP. The remaining friction is outside the web: some older desktop software, upload forms and print shops still reject it, and email clients are inconsistent. Files meant for maximum interoperability (attachments to strangers, government portals) are still safer as JPG or PNG.

The cheat sheet

Photograph for the web: WebP lossy, or JPG where compatibility rules. Screenshot or anything with text: PNG, or WebP lossless. Logo or graphic needing transparency: PNG, or WebP. Image to email to an unknown recipient: JPG for photos, PNG for the rest.

And the meta-rule that outlives every format war: keep your master copy in the highest quality you have (the original photo, the layered design file, the lossless export) and treat every compressed file as a disposable output you can regenerate. Formats change; the master is what you will thank yourself for.