PNG Converter — Free, Fast & Private
PNG (Portable Network Graphics) is the standard format for images that need transparency, sharp edges, or lossless quality. It is the go-to choice for screenshots, logos, UI elements, illustrations, and any graphic with text. MiniPx is a free PNG file converter that works in both directions: any image format to PNG, and PNG out to JPG, WebP, or AVIF — all in your browser with no upload required.
Converting to PNG makes sense when you need transparency support (alpha channel), when an application requires PNG specifically, when you are preparing images for further editing, or when you need pixel-perfect quality without compression artifacts. PNG files are larger than JPEG or WebP, but that trade-off is worth it for lossless quality.
Converting from PNG makes sense when you need smaller files for web delivery, email, or storage. PNG to WebP gives you 25-35% smaller files while keeping transparency. PNG to JPG produces the smallest files but drops transparency. And PNG compression can reduce file sizes by 40-70% without changing format.
When to use PNG vs other formats
Use PNG for: Screenshots, logos, icons, illustrations, UI mockups, images with text, anything with transparency, images that will be edited further, print graphics with sharp edges.
Use JPEG for: Photographs, textures, images with complex colour gradients, social media uploads, email attachments where small file size matters.
Use WebP for: Web delivery when you need the best balance of quality and file size. WebP supports both transparency and lossy compression, combining advantages of PNG and JPEG. See the image converter hub for all format options.
How PNG conversion works in MiniPx
MiniPx uses the browser Canvas API to decode source images and re-encode them as PNG. For most formats (JPEG, WebP, BMP, AVIF, HEIC), the browser handles decoding natively. For SVG files, MiniPx rasterizes the vector at the size the file declares (its width and height, or its viewBox, or 1024 × 1024 when it declares neither); the Max width setting can shrink that but never enlarges it.
The entire conversion happens in your browser tab. No files are uploaded to any server. This means conversion is instant (no upload/download wait) and private (no third-party access to your images). It also means your device sets the ceiling rather than a server: the free tier converts 5 files per batch and Pro removes that cap, with a 200 MB limit per file. There is no daily quota and no monthly credit on either tier.
Choosing a format to convert PNG to
The right target depends on what the image is and where it is going. For photographs with no transparent regions, convert PNG to JPG: it produces the smallest widely-accepted files, and every platform, form, and email client takes it. For graphics that need a transparent background at a smaller size, convert PNG to WebP — the alpha channel survives and files typically shrink 25-35%. For the deepest savings on modern websites, convert PNG to AVIF; it compresses hardest of the three with transparency intact, though some older browsers and desktop applications still cannot open it. And for one destination no ordinary format serves — website favicons and Windows icons — convert PNG to ICO, which packs several resolutions of your PNG into a single multi-size .ico file.
If you are unsure, the tool can advise you. After a conversion, MiniPx checks whether a different format would have been at least 15% smaller and offers it as a one-click option. It never switches formats silently — the choice stays yours.
What happens to transparency
Transparency is the detail most converters get wrong, so it is worth being precise. PNG, WebP, and AVIF all carry an alpha channel, so converting between them preserves transparent regions exactly. JPEG has no alpha channel at all: when you convert PNG to JPG, MiniPx composites the image over a white background — the behaviour most documents, forms, and email clients expect. In the other direction, converting a JPG to PNG gives the file the capacity for transparency but does not create any; an opaque photo stays opaque.
Batch PNG conversion
A PNG file converter earns its keep in bulk: a folder of exported screenshots, a designer's asset handoff, a set of product photos. Drop several files at once — they can even be different source formats — and MiniPx converts the whole queue to your chosen output in one run. The free tier processes 5 files per batch with no daily cap; Pro removes the per-batch limit. Multi-file results download together as a single ZIP archive, and each row shows the original and converted size so you can see exactly what changed.
What conversion does to image quality
Converting to PNG is lossless: every pixel of the decoded source is preserved exactly. What it cannot do is restore detail a lossy format already discarded — a heavily compressed JPEG converted to PNG is a faithful copy of the compressed image, artifacts included. Converting from PNG is the reverse case: because PNG sources carry no compression artifacts, they are the ideal input for JPEG, WebP, or AVIF encoding, and the Gentle, Smart, and Tiny presets let you decide how much size reduction to trade for quality. If you need a smaller file that still keeps every pixel, compress it losslessly instead of converting it.
Two side effects worth knowing about. Re-encoding through the browser canvas strips EXIF metadata — camera model, GPS location, timestamps — from the output, a quiet privacy win. And conversion never changes resolution on its own: the output keeps the source's pixel dimensions, with SVG the one exception: it has none, so it is rasterized at the size the file declares.
Reducing PNG file sizes
PNG files can be large — especially screenshots and high-resolution graphics. If your converted PNG is too big, use the PNG compressor to reduce it by 40-70% through colour quantisation (reducing the palette from 16.7 million colours to 256). For most screenshots and UI graphics, this reduction is invisible. For photos where PNG is overkill, switch to JPEG or WebP for dramatically smaller files.
PNG converter results on real files, measured
| File | Before | After | Change | Background |
|---|---|---|---|---|
| 12 MP phone photo | JPG · 4032 × 3024 px · 3.73 MB | PNG · 4032 × 3024 px · 16.3 MB | 4.4× larger | — |
| Scanned signature | JPG · 2041 × 617 px · 109.1 KB | PNG · 2041 × 617 px · 50.0 KB | 2.2× smaller | — |
| Screenshot (PNG) | PNG · 1280 × 800 px · 88.1 KB | PNG · 1280 × 800 px · 69.9 KB | 21% smaller | — |
| Logo SVG (width/height in px) | SVG · vector · 850 B | PNG · 480 × 160 px · 23.1 KB | 27.8× larger | Kept transparent |
Measured 2026-10-07 in Chromium 145.0.7632.6 by running this page's converter with its default setting (PNG) on each file. The photos and scans are CC0 or public-domain files from Wikimedia Commons; the screenshot is MiniPx's own; the SVGs are small hand-written files, each declaring its size a different way. Sizes are shown as the tool shows them (1 KB = 1,024 bytes).
