Free Online PNG Converter —
JPG, WebP, AVIF, SVG, PDF and More
Swift PNG is a 100% browser-based PNG converter. Drop a PNG, pick a target — JPG, WebP, AVIF, SVG, PDF, GIF, BMP, TIFF, or ICO — and the conversion runs locally on your device. No upload, no signup, no watermark.
Batch up to 100 files. Typical PNG → WebP output is 75–85% smaller than the source.
Privacy first — verifiable
Open DevTools → Network. 0 image bytes leave your device.
9 target formats from one PNG
JPG · WebP · AVIF · SVG · PDF · GIF · BMP · TIFF · ICO
Compress PNG
Reduce PNG file size while preserving quality
Resize PNG
Scale PNG images by pixel or percentage
Crop PNG
Trim PNG images to exact aspect ratios
Remove Background
Make PNG backgrounds transparent instantly
PNG → 9 Formats: How They Compare
A side-by-side breakdown of every format Swift PNG can output from a PNG. Use it to pick the right target before you convert.
| Target | Transparency | Typical size cut vs PNG | Lossy? | Best for | Browser support |
|---|---|---|---|---|---|
| JPG | No | 70–90% | Yes | Photos without alpha | Universal |
| WebP | Yes (lossy + lossless) | 60–85% | Both | Web hero, UI, products | All modern, Safari 14+ |
| AVIF | Yes | 75–95% | Both | Maximum compression, future-proof | Chrome 85+, Safari 16+ |
| SVG | Vector (no raster alpha) | n/a (path data) | n/a | Logos, icons, line art | Universal |
| Yes (embedded) | 0–20% | n/a | Documents, print | Universal | |
| GIF | 1-bit only | Often larger | Lossy palette | Animations only | Universal |
| BMP | Yes (32-bit) | Almost always larger | No | Legacy Windows tools | Universal |
| TIFF | Yes | Variable | Both | Print, archival | Limited browsers |
| ICO | Yes | Smaller (multi-res) | No | Favicons | Universal |
Numbers are typical ranges measured on real-world PNGs at quality 80. Actual results depend on image content (photo vs flat color vs line art).
How to Convert Images
Simple, fast, and secure process.
Upload
Drag & drop files or folders (PNG, JPG, WebP, BMP) into the zone.
Adjust
Set quality (0-100%), target size, or resize dimensions.
Convert
Auto-processing starts instantly via WebAssembly engine.
Download
Save individually or download all as a ZIP archive.
When NOT to convert your PNG
Picking the wrong target format silently corrupts what makes your PNG useful. Skip the conversion when any of the following applies.
-
Don't convert PNG → JPG if the image has transparency
JPG has no alpha channel. Transparent areas become solid white (or your fill color). Use WebP, AVIF, or SVG instead.
-
Don't convert PNG → SVG if it's a photo or noisy gradient
Vector tracing works on edges and flat regions. Photographs trace into thousands of fragmented paths — bigger than the original PNG and visually worse.
-
Don't convert PNG → AVIF for Safari < 16 without a fallback
AVIF gives the smallest files but older Safari versions cannot decode it. Use a `<picture>` element with a WebP or JPG fallback when targeting older browsers.
-
Don't compress a screenshot below ~80% if it contains text
Text edges break first under quantization. Keep quality ≥ 80 for screenshots, UI captures, and documents.
-
Don't convert PNG → GIF for static images
GIF is limited to 256 colors and almost always produces larger files than the source PNG. Use it only for animations.
-
Don't re-compress an already-lossy file as PNG
PNG is lossless: re-saving a JPG as PNG just freezes JPG artifacts at a larger size. Stay in the lossy format or restart from the original.
Common PNG conversion problems
Direct fixes for the issues that come up most often when converting PNG to other formats.
PNG file too large for the web?
Convert to WebP or AVIF for 70–90% smaller files at near-identical quality. Or use Compress PNG to optimize without changing format.
Transparency lost after conversion?
JPG has no alpha channel. Switch the target to WebP, AVIF, or SVG to keep alpha intact.
Alpha pixels turned solid black or white?
You converted to JPG. Re-run the conversion with WebP or AVIF as target. If you must use JPG, set a background color in Settings instead of accepting the default fill.
PNG to SVG looks blocky?
Vector tracing works on logos, icons, and line art. Lower the threshold for high-contrast images, or convert photos to JPG/WebP instead.
PNG to ICO blurry below 32 px?
Use a source PNG that is already 32 × 32 or 64 × 64. Down-scaling a 1024 px PNG to a 16 px favicon throws away the detail Windows uses.
AVIF output looks dark or shifted?
Old AVIF encoders mishandle the sRGB color profile. Swift PNG embeds sRGB explicitly — re-export and verify in Chrome 100+ or Safari 16+.
PDF page size is wrong?
PDF inherits its page size from the PNG's pixel dimensions divided by DPI. Set DPI in Settings (default 96) before converting.
Privacy & engineering — what runs on your device
Swift PNG runs entirely in your browser. No image bytes are sent to any server during conversion — you can verify this yourself.
Verify it yourself
Open DevTools → Network tab, run a conversion. The number of outgoing image requests must remain at 0. The only network traffic is for the page itself, on first load.
Metadata & color
EXIF and other metadata are stripped on conversion by default. The output uses the sRGB color profile. There is no telemetry on uploaded images.
Encoders we use
Conversion is performed via the Canvas API and WebAssembly modules running locally:
- JPG Canvas toBlob → libjpeg-turbo (browser-native)
- WebP Canvas toBlob → libwebp (browser-native)
- AVIF Canvas toBlob → libavif (browser-native, Chrome 85+ / Safari 16+)
- SVG Custom potrace-inspired tracer (open-source, see /utils/pngToSvg.ts)
- HEIC input heic2any (WASM)
Privacy Architecture:
The "Local-First" Difference
Most online converters upload your private files to a remote server. Swift PNG is different. We engineered a serverless solution using WebAssembly.
Local Processing
Your browser does the heavy lifting using compiled WASM modules. It's faster because there's no upload/download latency.
Zero Server Upload
Check your network tab—files never leave your device. We literally cannot see, store, or share your images.
Offline Capable
Once the page manages to load, you can disconnect Wi‑Fi and continue converting. The app lives in your browser cache.
No Data Retention
There is no cloud storage to hack. Closing the tab instantly wipes all processed data from your browser's memory.