Image Format Converter

Free online image format converter supporting PNG, JPEG, WebP conversion with adjustable quality and size. Convert images directly in your browser with privacy-friendly no-upload processing.

Choose an image or drag & drop here
Drag an image file into the box to start

Conversion Settings

Result Size: -

Preview

Image Formats and Conversion

Settings Usage

  • Quality: Applies to JPEG/WebP only, range 0.1–1. Higher values mean less compression, better visual quality, and larger files. Lower values increase compression and reduce file size but may introduce artifacts. PNG is lossless; the quality slider does not apply.
  • Keep Aspect Ratio: When enabled, changing width or height automatically adjusts the other dimension based on the original ratio to avoid distortion. Disable it to freely set width and height.

Supported Output Formats and Principles

PNG (Portable Network Graphics)

  • Principle: Lossless compression (DEFLATE/zlib) with chunked storage; supports palette, grayscale, truecolor, and alpha transparency.
  • Pros: Lossless, transparency support, interlacing (Adam7), excellent browser compatibility.
  • Cons: Larger file sizes; not ideal for photo-heavy content distribution.
  • Use cases: Icons, UI, illustrations, transparent images, assets requiring lossless quality.

JPEG (JFIF)

  • Principle: Discrete Cosine Transform (DCT) + quantization + entropy coding; optional chroma subsampling (e.g., 4:2:0) to improve compression; no transparency support.
  • Pros: High compression efficiency and small file sizes; great for photos and continuous-tone images; widely supported.
  • Cons: Lossy—repeated saves accumulate artifacts; no transparency; heavy compression may cause blocking/ringing.
  • Use cases: Web photos, galleries, backgrounds where file size is a priority.

WebP (Google)

  • Principle: Lossy mode based on VP8 (block prediction + transform coding); lossless mode uses near-pixel prediction with entropy coding; supports alpha transparency and animation.
  • Pros: Smaller sizes at similar perceived quality compared to JPEG/PNG; transparency support; widely supported in modern browsers.
  • Cons: Older devices/browsers may have limited support; extreme lossless cases may be larger than PNG.
  • Use cases: Web image optimization, transparent assets with reduced size, bandwidth-sensitive mobile scenarios.

Recommendations

  • Need transparency with high fidelity: prefer PNG or WebP (lossless/transparent).
  • Photo size optimization: choose JPEG or WebP (lossy), tune quality upward until acceptable at minimal size.
  • Bulk web asset optimization: prefer WebP; keep PNG/JPEG fallback for legacy environments if necessary.

Privacy & Security

Conversion happens locally in your browser. No data is uploaded to the server.

References