What happens to transparency when converting PNG to JPEG?

JPEG does not support transparency. When converting a PNG with a transparent background to JPEG, the tool fills transparent areas with a solid color — white by default. You can change this background color in the settings before converting. For images that need to keep transparency, convert to WebP or PNG instead.

How much smaller will my images be after converting to WebP?

WebP typically achieves 25–35% smaller file sizes than JPEG at equivalent visual quality, and 50–80% smaller than lossless PNG for photographic content. The actual savings depend on image content. Photos with gradients compress best; images with sharp text or flat colors may see smaller improvements.

Can I convert multiple images at once?

Yes. You can select up to 50 images at once using the file picker or drag multiple files onto the drop zone. All images are converted with the same settings (format, quality, background color). Download individual files or click 'Download All as ZIP' to get everything in one archive.

Image Tool

Image Converter

Convert JPEG, PNG, WebP, GIF, and BMP images — individually or in bulk. Set quality, handle transparency, and download as ZIP. Nothing uploaded to any server.

Drop images here or click to select

Up to 50 images · JPEG, PNG, WebP, GIF, BMP supported

JPEG PNG WebP GIF BMP → JPEG PNG WebP

Quality

1 (smallest)100 (best)

PNG is lossless — quality slider not applicable

Transparency Background

Applied when converting transparent PNG/WebP to JPEG. Ignored for PNG/WebP output.

JPEG vs PNG vs WebP — Quick Comparison

Choose the right output format for your use case.

Feature	JPEG	PNG	WebP
Compression	Lossy	Lossless	Lossy & Lossless
Transparency (Alpha)	No	Yes	Yes
Animation	No	APNG only	Yes
Typical file size (photo)	Medium	Large	Smallest
Browser support	Universal	Universal	All modern (95%+)
Best for	Photos, social media	Screenshots, logos, icons	Web images (all types)
Email client support	Universal	Universal	Limited

How to Convert Images

Batch convert dozens of images in under a minute.

Drop or Select Images

Drag multiple images onto the drop zone or click to open the file picker. Select up to 50 files at once — JPEG, PNG, WebP, GIF, and BMP are all accepted.

Choose Output Format

Click JPEG, PNG, or WebP. JPEG for photos. PNG for images that need transparency or lossless quality. WebP for the smallest file size on modern browsers.

Set Quality

Drag the quality slider. 75–85 is the sweet spot for JPEG and WebP — smaller files, minimal visible loss. PNG ignores quality (it's always lossless).

Set Background Color (JPEG)

If converting transparent PNGs to JPEG, pick a background color. Transparent pixels will be filled with this color since JPEG doesn't support alpha. Default is white.

Click Convert All

The tool processes every image using the Canvas API. A progress bar tracks batch conversions. File size before and after are shown with a percentage change for each file.

Download

Download files individually with the per-row button, or click Download All as ZIP to get every converted image bundled in a single archive.

How This Tool Works

All conversion happens in your browser using native Web APIs.

🖼️

Canvas API Encoding

Each image is loaded via FileReader, drawn onto a Canvas, and re-encoded with canvas.toBlob(mimeType, quality). The browser's built-in encoder handles the format conversion.

🎨

Transparency Handling

For PNG/WebP → JPEG, the canvas is pre-filled with your chosen background color before drawing the image. This replaces transparent pixels with a solid color, since JPEG has no alpha channel.

📦

ZIP via JSZip

Batch ZIP download uses the JSZip library (loaded from CDN). Each converted Blob is added to the archive, then the ZIP is generated in-memory and offered as a single download.

⚡

Sequential Processing

Files are converted one at a time using async/await to avoid overwhelming the browser's main thread. A progress bar reflects completion. Each conversion is independent — one failure doesn't stop the batch.

🔍

GIF & BMP Support

The browser can decode GIF (first frame) and BMP files natively via the Image element. The canvas then re-encodes to JPEG/PNG/WebP. GIF animation is not preserved — only the first frame is converted.

🔒

100% Private

No image data leaves your device. FileReader reads files into browser memory, Canvas processes them, and Blobs are downloaded directly. Zero network requests are made during conversion.

Frequently Asked Questions

Common questions about image format conversion.

This can happen when: (1) You're converting a JPEG to PNG — PNG is lossless and stores every pixel, so it's almost always larger than the JPEG it was made from. (2) You're converting a small or already-compressed file to WebP at high quality. (3) The source image is highly optimized in its original format. Converting between lossy formats (JPEG ↔ WebP) at high quality can sometimes produce larger output. Try lowering the quality slider for lossy formats.

No. Converting a JPEG to PNG stores the already-compressed pixels losslessly, but it cannot recover detail that was discarded when the JPEG was created. The output will look identical to the JPEG (or very similar) but at a much larger file size. Converting from lossy to lossless preserves what's there — it doesn't restore what was lost. For maximum quality, always start from the original uncompressed or RAW source.

Use WebP for images on web pages when you control the serving environment (own website, blog, web app). WebP gives 25–35% smaller files than JPEG at the same quality, which directly improves page load speed. Use JPEG when sharing via email, messaging apps, or platforms that don't consistently preserve WebP (some social platforms, older email clients). In 2025, all major browsers support WebP, so it's the default choice for web delivery.

HEIC/HEIF support depends on your browser and operating system. Safari on macOS 12+ and Chrome 105+ on some platforms support HEIC decoding. If your browser supports it, the Image element will load the file and the Canvas will convert it. If not, you'll see a load error. For reliable HEIC conversion across all platforms, a dedicated native app or a server-side tool is more dependable than a browser-based converter.

The tool processes up to 50 files per batch. Each file is loaded into browser memory during conversion, so very large batches of high-resolution images may use significant RAM. If you experience slowness or crashes with large batches, try converting in smaller groups of 10–20 files. After completing a batch, click "Clear all" to free memory before adding the next group.

Yes. The ZIP is generated entirely in your browser by JSZip — an open-source JavaScript library. The archive contains only the image files you converted, with no executable code. The file is created in browser memory and downloaded directly to your device. The JSZip library is loaded from jsDelivr CDN (a well-known, audited CDN), and its source code is publicly available on GitHub.

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