kittokit
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Runs local · no upload

Compare and Convert Image Formats — WebP, AVIF, PNG, JPG

Which image format fits? Compare, convert, ship.

Drop file here

max. 50 MB

PNGJPG
Settings
85
smaller sharper

How It Works
  1. 01

    Select a file

    Drag your file into the drop zone or click to browse.

  2. 02

    Local processing

    The tool processes your file entirely on your device.

  3. 03

    Download result

    Download the finished result with a single click.

Privacy

Your files never leave your device. All processing happens locally in your browser.

Four image formats cover the modern web: PNG for transparency, JPG for photos, WebP as the universal web standard, AVIF for maximum compression. This tool helps with the comparison (browser support, file size, quality) and converts directly — or jumps to dedicated tools for your specific format pair. Runs entirely offline, no server upload.

Format pairs
4dedicated tools
Typical savings
25–80%
Processing
in browser
01 — How to Use

How do you use this tool?

  1. If you know what you need — use a dedicated tool below (e.g. JPG to WebP for photos)
  2. If you're unsure — pick the target format above, drop your image into the zone, and compare the result
  3. Set quality on the slider (default 85). Preview and size update live
  4. Click <em>Download</em> when the result fits — or try a different target format to compare

Which Format Do I Need?

Choosing an image format comes down to three dimensions: browser reach, file size, and use case. Here’s the quick decision guide:

  • Photos for web delivery: JPG to WebP for most cases, JPG to AVIF for hero images with maximum compression.
  • Logos, icons, screenshots with transparency: PNG to WebP as the web standard, PNG to AVIF for maximum bandwidth savings.
  • Universal compatibility (legacy CMS, print, older tools): keep PNG or JPG.
  • Progressive delivery with fallback chain: AVIF as the primary source, WebP as the second source, JPG/PNG as the fallback inside <picture>.

If you’re not sure, use the format picker above the drop zone — you’ll see a direct size comparison on the live output and can pick the right format based on your actual file.

How Do WebP and AVIF Compare?

Both formats are modern successors to JPG and PNG. WebP derives from the VP8 video codec and has shipped on the web since 2010, AVIF uses the modern AV1 codec and arrived in 2019.

CriterionWebPAVIF
Introduced2010 (Google)2019 (Alliance for Open Media)
Typical savings vs JPG25–35%40–50%
Typical savings vs PNG50–70%70–85%
Browser reach~97% global~95% global
Safari supportiOS 14 / macOS 11iOS 16.4 / macOS 13.3
Encoding speedFastSlower (AV1-based)
TransparencyYes (lossy + lossless)Yes (lossy + lossless)
HDR / 12-bit colorNoYes
LicensingBSD (royalty-free)Royalty-free (AOMedia)

Pick WebP for standard web images, bulk conversion of legacy assets, older devices in your audience, or CMS setups that don’t yet serve AVIF.

Pick AVIF for hero images, bandwidth-constrained markets (mobile-first, emerging markets), or when the <picture> element with a progressive fallback chain is in play.

Which Format Pairs Are Most Common?

Instead of reaching for the general-purpose converter, a dedicated tool often saves clicks and helps you internalize the source/target trade-offs.

  • PNG to WebP — when you optimize logos, icons, or screenshots. Alpha channel preserved, typical savings 50–70%.
  • JPG to WebP — when you shrink photos for web performance. The standard for blog headers, product photos, gallery images.
  • PNG to AVIF — when maximum compression with transparency matters. Hero logos, large icon sprites, banners with cut-out subjects.
  • JPG to AVIF — when you optimize hero photos to the smallest size. Photography portfolios, e-commerce hero shots, mobile-first delivery.

How Does Progressive Delivery Work With the Picture Element?

The <picture> element lets the browser pick the best available format. Combining AVIF + WebP + JPG gives every visitor the optimum — modern devices get AVIF, Safari iOS 15 gets WebP, the rare legacy client gets JPG.

<picture>
  <source srcset="/img/hero.avif" type="image/avif" />
  <source srcset="/img/hero.webp" type="image/webp" />
  <img src="/img/hero.jpg" alt="Hero description" width="1280" height="720" />
</picture>

Important: set width and height on the <img> so the browser knows the reserved space before the asset loads — this prevents layout shifts on Largest Contentful Paint.

How Does the Privacy-First Browser-Only Pipeline Work?

Conversion runs entirely client-side through the built-in image encoding pipeline. Your file is never sent to, stored on, or analyzed by a server. No tracking, no third-party cookie banner, no sign-up.

After the first load, the page works offline — the browser APIs needed have shipped in all modern browsers since 2018. For sensitive images (ID scans, medical photos, internal corporate documents), this is the decisive advantage over web converters that require an upload.

Other tools from the kittokit ecosystem around image optimization:

  • PNG to WebP — dedicated tool for logos, icons, and screenshots with transparency.
  • JPG to WebP — dedicated tool for photos and web performance.
  • PNG to AVIF — maximum compression with preserved transparency.
  • JPG to AVIF — smallest file for hero photos and mobile delivery.
  • Background Remover — cut subjects out of photos with on-device ML, no upload.

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