PNG format explained: lossless, transparent, often too big

What PNG is

PNG stores every pixel exactly. Nothing is thrown away, so a screenshot, logo or diagram survives any number of saves and edits. It also carries an alpha channel: pixels can be fully or partly transparent.

That exactness is the problem for photographs. A camera image saved as PNG is often five to ten times the size of the same picture as JPG, with no visible difference.

Use PNG when

• Screenshots, UI mock-ups, charts, logos and anything with text or hard edges.
• Images that need transparency and must open everywhere (WebP transparency is newer).
• Master copies you will keep editing.

Avoid PNG when

• Photos for the web or messaging. A JPG or WebP is far smaller and looks the same.
• Large batches for email or upload limits: PNG rarely compresses enough.

How ConvertX handles PNG

• Reads and writes PNG on every platform, with transparency preserved.
• "Exact quality" in the compressor recompresses PNG losslessly, which often shaves 10–30 % with zero change to the pixels.
• In "Smaller files" mode, BMP and TIFF inputs are also saved as PNG, so nothing lossy touches graphics.
• "Keep photo details" writes EXIF into the PNG when the source had any.

Extensions: .png. Metadata: can carry EXIF when "Keep photo details" is on.

Need the file smaller rather than in another format? See compress PNG.