JPG to PNG Converter: Free, Private, No Upload

What actually changes in this conversion

• Moving from a lossy format to a lossless one stops any further quality loss but cannot restore detail already discarded.
• JPG has no alpha channel, so every pixel is already opaque.
• Expect the PNG file to be far larger than the JPG source.
• EXIF, GPS and camera data are stripped on every conversion. That is good for privacy, but you lose capture dates.

About JPG: history and technical details

Created in 1992 by the Joint Photographic Experts Group and standardised as ISO/IEC 10918. It became the default image format of the early web because it offered photographic compression when storage was expensive. Still the most widely used photo format 30+ years later.

Technical: 8x8 block Discrete Cosine Transform with 4:2:0 chroma subsampling by default. Baseline supports 8-bit per channel. Progressive loads in waves. Maximum dimensions 65,535 by 65,535 pixels. Maximum 16.7 million colours.

Real-world size: A 12-megapixel photo at quality 85 is typically 2-4 MB. The same photo as PNG is 18-25 MB, as BMP is 36 MB. JPG is 60-80% smaller than PNG for photographs.

Popular tools: Adobe Photoshop, GIMP, Affinity Photo, Lightroom, macOS Preview, Windows Photos, ImageMagick, FFmpeg.

Alternatives: WebP (25-35% smaller), AVIF (30-50% smaller), HEIC (50% smaller, Apple only), PNG (lossless, 5-10x larger).

About PNG: what you get

Created in 1995 as a free, patent-unencumbered replacement for GIF after Unisys began charging royalties for LZW compression. Became a W3C Recommendation in 2003. The signature bytes are 89 50 4E 47 0D 0A 1A 0A — "PNG" with newlines designed to catch file corruption.

Technical: Uses DEFLATE (LZ77 + Huffman) compression. Two main modes: 8/16-bit truecolour with alpha, and 8-bit indexed with up to 256 colours. Filters per scanline (None, Sub, Up, Average, Paeth) before DEFLATE for better ratios.

Real-world size: A 1920x1080 screenshot is 200-600 KB as PNG. As JPG at quality 85 it is 100-300 KB but with blurry text. A 12-MP photo is 18-25 MB as PNG, 2-4 MB as JPG. PNG wins on text, JPG wins on photos.

Popular tools: Adobe Photoshop, GIMP, Figma, Sketch, Snipping Tool, macOS Screenshot, ImageMagick, pngquant, oxipng.

Alternatives: WebP lossless (20-30% smaller), AVIF (better for photos), JPG (photos only), SVG (vector graphics).

Browser and software compatibility

JPG: Opens in every browser, operating system, camera, editor and print service. PNG: Opens in every browser and image editor.

PNG output opens in virtually every browser, operating system and editor.

Why people move away from JPG

• JPG cannot store transparency, so logos, cut-outs and interface assets need another format.
• Every re-save of a JPG throws away more detail, a problem for images edited repeatedly.
• Sharp edges and text show ringing artefacts in JPG, and newer codecs give smaller files at the same visual quality.

Why people choose PNG

• PNG keeps every pixel, making it safe for screenshots, diagrams, logos and anything with text.
• It stores full alpha transparency, including soft shadows and anti-aliased edges.
• Lossless output means you can keep editing without generational loss.

Common mistakes with JPG

• Re-saving a JPG multiple times compounds quality loss — always keep the original
• Using JPG for logos with text causes visible ringing around letters
• Setting quality above 95 rarely improves visual quality but enlarges files

Common JPG to PNG scenarios

• Preparing an image for editing: PNG stops further compression loss while you retouch.
• Adding transparency later: JPG has no alpha channel, so converting to PNG is the first step before cutting out a subject.
• Screenshotting a JPG: PNG prevents further loss when annotating.

Best practices for keeping quality

• If you still have the original camera file, convert from that. A JPG already compressed hard has little detail left to preserve.
• Converting a lossy file to PNG stops further loss but does not restore detail already discarded. Expect a much larger file with no visible gain.
• PNG suits screenshots and flat graphics. For photographs, a lossy format is usually the better trade.
• Resize before converting if the image will be shown small. A 4000 pixel photo displayed at 800 pixels wastes bytes in any format.
• Check the result at 100 percent zoom, especially around text, edges and gradients, before you replace any originals.
• Keep your original files. Conversions to a lossy format cannot be undone.
• When you convert a set of images, use the same quality setting for the whole batch. The converter handles up to 20 files at once.