CalcaTools

PNG to JPG Converter

A free tool to convert PNG images to JPG (and vice versa) instantly in your browser. Adjust JPEG quality, pick a background color for transparency, and batch-convert multiple files. Nothing is uploaded to a server.

Last updated: June 2026 · Free · No sign-up required

upload_file

Drag & drop images here

or browse files · Supports multiple files

Frequently Asked Questions

What happens to PNG transparency when converted to JPG?

The JPG format does not support transparency. When converting a transparent PNG to JPG, the transparent areas are filled with a solid background color, which you can custom-select using the background color picker (default is white).

Can I convert multiple PNG files at the same time?

Yes, you can drop or upload multiple images simultaneously. The batch converter will process all files and trigger individual downloads for each output image.

Is my image data kept private?

Yes. The conversion processes are completely local using HTML5 canvas inside your browser. No files are uploaded to any server, meaning your images remain fully private.

Quick reference

AspectPNGJPG
CompressionLosslessLossy
TransparencyYesNo (flattened)
Photo file sizeLarge3–10× smaller
Best forGraphics, screenshots, logosPhotos

Interpretation guide

Conversion choiceTip
Quality80–90% is visually lossless for photos
Background colourTransparency flattens onto it (white default)
Don’t convertText/graphics PNGs gain artifacts as JPG

Formula & methodology

Formula: JPG = canvas re-encode of PNG at chosen quality; alpha composited onto background colour

  1. Drop a PNG — conversion is local; nothing uploads.
  2. Pick the JPG quality and the background colour used where the PNG was transparent.
  3. Download the converted JPG and compare sizes.

Worked example: a 3.1 MB PNG screenshot of a photo converts to a ~400 KB JPG at 85% (−87%); its transparent corners flatten onto the chosen white background.

Frequently asked questions

Why convert PNG to JPG?
File size — for photographic content JPG is typically 3–10× smaller than PNG at indistinguishable quality, which matters for web pages, emails and uploads with size limits.
What happens to transparency?
JPG has no alpha channel, so transparent areas are flattened onto a background colour you choose (white by default). If you need transparency preserved, keep PNG or use WebP.
Does converting lose quality?
JPG is lossy, but at 85–90% quality the loss is invisible for photos. Avoid converting text-heavy graphics or screenshots of UI — JPG artifacts show around sharp edges.
Is the conversion private?
Yes — the canvas API converts the file inside your browser. No server sees the image.
When should I keep PNG instead?
Logos, charts, UI screenshots, anything with sharp edges, flat colour or transparency. PNG is lossless there and often smaller than JPG for that content type.

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