Image Formats Compared: JPG vs PNG vs WebP vs AVIF (2026)

The image format you choose affects page load time, SEO ranking (Core Web Vitals), bandwidth costs, visual quality, browser compatibility and accessibility. In 2026, the answer is no longer “just use JPG”, modern formats save 50-70% on file size at equivalent quality.

This guide compares the four formats that matter today: JPG, PNG, WebP, AVIF. Plus a note on HEIC (Apple), TIFF (print), and SVG (vector).

Quick reference table

Format	Compression	Transparency	Animation	Browser support (2026)	Best for
JPG	Lossy	❌	❌	100%	Photos, email, max compatibility
PNG	Lossless	✅	❌	100%	Logos, icons, screenshots
WebP	Lossy or lossless	✅	✅	96%	Modern web (default in 2026)
AVIF	Lossy or lossless	✅	✅	92%	Performance-critical web
HEIC	Lossy	✅	✅	iOS/macOS only	Apple device storage
GIF	Lossless	1-bit only	✅	100%	Legacy animations only
SVG	Lossless vector	✅	✅	100%	Logos, icons, illustrations (any size)

JPG (JPEG)

Born 1992. Universally supported. Lossy compression with quality slider (1-100). At quality 75-85, indistinguishable from original to the human eye while being 5-10× smaller than the source RAW.

Strengths:

• Universal compatibility (literally everywhere).
• Tiny files for photos.
• Mature, well-understood compression.

Weaknesses:

• No transparency (must use solid background).
• Compression artefacts at low quality (blockiness, halos).
• No animation.
• Older standard, superseded for modern web.

Use it when: emailing photos, sending to old systems, max compatibility matters, no transparency needed.

PNG (Portable Network Graphics)

Born 1996. Lossless compression. Two variants: PNG-8 (256 colours, GIF replacement) and PNG-24 (16 million colours, photo-quality). Both support transparency (8-bit alpha channel), the killer feature.

Strengths:

• Lossless: bit-perfect copy of original, no artefacts ever.
• Transparency support (alpha channel).
• Crisp at any zoom level (no compression blockiness).
• Universal compatibility.

Weaknesses:

• Much larger than JPG for photographs (2-5× bigger).
• No animation (use APNG, but support is mixed).
• Less efficient compression than modern formats.

Use it when: logos, icons, screenshots, line art, illustrations, anywhere you need crisp lines or transparency.

WebP

Created by Google in 2010. Lossy mode rivals JPG with ~25-35% better compression at same quality. Lossless mode rivals PNG with ~25% better compression. Animation mode rivals GIF with massively better quality and compression.

In 2026, WebP support is 96% globally, every modern browser (Chrome, Firefox, Safari 14+, Edge) supports it natively. Only ancient browsers and some email clients lack support.

Strengths:

• Best balance of compression efficiency, compatibility and feature set.
• One format covers lossy, lossless and animated needs.
• Supported by all modern image CDNs (Cloudinary, Imgix, Cloudflare Images).
• Free and open (royalty-free).

Weaknesses:

• Slightly slower decode than JPG (negligible on modern hardware).
• Some legacy software (Photoshop CS5 and older) requires plugin.
• Encoding marginally slower than JPG.

Use it when: anywhere on modern web. WebP should be your default in 2026 unless a specific reason argues otherwise.

AVIF (AV1 Image File Format)

Released 2019, based on the AV1 video codec. The most compression-efficient widely-supported format in 2026, typically 25-35% smaller than WebP at same quality.

Support in 2026: ~92% globally. All major browsers support it (Chrome 85+, Firefox 93+, Safari 16.4+, Edge). Some specific environments (email clients, very old enterprise software) don’t.

Strengths:

• Best compression of any widely-supported format.
• Supports HDR (high dynamic range, 10/12-bit colour depth).
• Supports transparency, animation.
• Open and royalty-free.
• Excellent quality even at very low bitrates.

Weaknesses:

• Encoding is slow (10-30× slower than JPG). Not great for request-time encoding.
• Slower decode than WebP (still milliseconds, but measurable).
• Slightly less compatible than WebP.
• Not yet ubiquitous in image editing software.

Use it when: performance-critical sites where every KB matters. Pre-encode at build time, serve with WebP and JPG fallbacks.

The 2026 best practice: <picture> with fallbacks

Don’t pick one format, serve the best one each browser supports:

<picture>
  <source srcset="/photo.avif" type="image/avif">
  <source srcset="/photo.webp" type="image/webp">
  <img src="/photo.jpg" alt="Description" width="1200" height="800" loading="lazy" decoding="async">
</picture>

Modern browsers pick AVIF, slightly older browsers fall back to WebP, very old browsers get JPG. All while sharing the same <img> semantic and alt text.

Frameworks automate this:

• Next.js: <Image> component handles AVIF/WebP/JPG automatically.
• Astro: <Image> from astro:assets does the same.
• Cloudinary / Imgix: serve based on Accept: image/avif request header.

What about HEIC?

HEIC (High Efficiency Image Container) is what your iPhone saves. Same compression family as AVIF (HEVC video codec). Excellent compression, supports transparency and HDR.

Problem: only Apple devices natively support HEIC. Windows, Android browsers, web servers, image software all need plugins or conversion.

Best practice: convert HEIC to JPG or WebP before sharing or web-hosting. HEIC to JPG does this in your browser.

What about TIFF, BMP, GIF?

• TIFF: pre-press / professional print archival. Massive files, no compression by default. Don’t use on web.
• BMP: legacy Windows format. No compression. Don’t use anywhere in 2026.
• GIF: 1-bit transparency, 256 colours, lossless. Animation works but inefficient, every modern alternative (WebP, AVIF, even MP4 video) is better. Only use for legacy compatibility.

What about SVG?

SVG is vector, not a competing format for photographs, but unbeatable for logos, icons, illustrations, charts. Resolution-independent (scales infinitely without quality loss), tiny file size for simple graphics, supports CSS styling and JS interaction.

Use SVG for: logos, icons (favicons), data visualisations, simple illustrations, any graphic that’s drawn rather than photographed.

Favicon Generator outputs SVG variants for modern browsers.

Decision tree for picking a format

1. Is it a logo, icon, or simple graphic? → SVG.
2. Photographic content with no transparency needed? → AVIF (build-time) → WebP fallback → JPG fallback.
3. Photographic content with transparency? → AVIF or WebP (both support alpha) → PNG fallback.
4. Logo, screenshot, or graphic with transparency? → PNG (or WebP-lossless for size).
5. Maximum email/legacy compatibility? → JPG (no transparency) or PNG (with transparency).
6. Animation? → WebP (or AVIF if newer browsers OK) → GIF only as last resort.

Real-world conversion paths

Photographer delivering to client: keep RAW master, deliver JPG quality 95 (web) or TIFF (print).

Webmaster optimizing existing site: bulk convert all PNGs/JPGs to AVIF + WebP at build time. Serve via <picture>.

E-commerce product photos: WebP quality 80 is the sweet spot. AVIF if your traffic profile justifies the encoding time.

Blog hero images: AVIF (with WebP and JPG fallback), Core Web Vitals reward you for it.

Social media cover image: JPG or PNG. Most platforms re-encode anyway, so don’t bother with WebP/AVIF at upload.

Email signature: PNG (max compatibility, transparency support) or JPG (smaller).

Summary

In 2026, the modern web image stack is AVIF → WebP → JPG, served via <picture> with fallbacks, with PNG and SVG holding their roles for graphics and logos.

For one-off conversions, Convert Image handles the full matrix locally, your image never reaches a server, supports JPG, PNG, WebP and AVIF as both input and output. Use it as needed, but understand what each format optimises for so your choices are deliberate.