filehugger.comJPG, PNG or WebP: choosing the right image format for the job
Format advice is usually folklore. We measured ours with the same encoders these tools use, so this guide's claims come with numbers.
Question 1 — Does it need transparency?
JPG has no alpha channel: converting a transparent logo to JPG flattens it onto a background, permanently. Keep transparency in PNG (universal) or WebP (smaller). This is the one rule with no exceptions.
Question 2 — Is it a photograph?
Never PNG. In our format study the photo was 1,022 KB as PNG versus 43 KB as JPG-85 — about 24 times larger for no visible benefit. Between the lossy pair, WebP came out 31% smaller than JPG on that same photo, and it beat JPG on every content type we tested. Use JPG to WebP when the destination is modern; fall back to JPG for maximum compatibility (email clients, old CMSes, government portals).
Question 3 — Is it a text-heavy screenshot?
The surprise in our data: on a text-heavy screenshot lossless PNG (176 KB) cost only about 1.7x the JPG-85 file (105 KB) — a far smaller premium than the 24x it costs on a photo — and JPG text always carries faint compression fuzz. For UI screenshots, receipts and anything someone will zoom into, PNG is the honest choice; WebP at quality 90 splits the difference when size matters.
Practical rules
- Sending photos by email? JPG or WebP at quality ~70 — see the Compress Image goal presets.
- Website images? WebP everywhere current browsers are the audience; the savings are 30%+ for free.
- Editing later? Keep a lossless master (PNG or the original) — every lossy re-save stacks damage.
- AVIF compresses better still, but browsers cannot encode it from a canvas at all — we measured that too, which is why we convert from AVIF and offer no convert-to-AVIF tool.
Tools used in this guide
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