FILE SIZE
Get a PNG under 25 MB
Smaller files involve real tradeoffs. Here is what our automatic compressor changes—and what it does not.
Know the limit you are checking
POD IMG Tools uses decimal megabytes: 25 MB means 25,000,000 bytes. A successful under-25-MB result is strictly smaller than that number. This is slightly more conservative than a 25-MiB limit.
Start with a full-color PNG
The compressor first asks your browser to encode the image as a full-color PNG. It compares that with the source when the source is already a PNG at unchanged dimensions, and keeps the smaller candidate. Sometimes a file is already efficient, so there is no useful size saving without changing the image.
Use palette optimization only when necessary
If the full-color result is too large and automatic optimization is enabled, the tool groups similar colors into an adaptive palette. A palette needs fewer bits per pixel than a full RGBA image. The tool tries progressively smaller palettes until a candidate meets your chosen size limit or returns a clear error.
Palette reduction is not lossless. Colors can shift, subtle gradients can show banding, and soft alpha values may change. Fully transparent areas remain transparent; fully opaque pixels are not deliberately turned translucent. Inspect edges on both dark and light backgrounds.
Choose full-color-only mode for sensitive artwork
For delicate gradients or brand-critical art, choose “Full color only — never reduce colors.” If the result cannot meet your limit, the tool reports the failure rather than silently reducing the palette. You can then use a larger limit or resize the dimensions yourself.
Do not confuse smaller bytes with smaller dimensions
PNG Compressor keeps the canvas dimensions. Merch Resizer intentionally changes them to 4500 × 5400. Custom Resizer makes that choice explicit. Check which tool you are using before uploading the final output.
Keep the original
The tool does not overwrite your source file. Keep your original layered or full-resolution design separately. Browser re-encoding may change color-profile and metadata handling, so archive the original rather than treating an optimized export as a master.
Technical references
W3C: PNG palettes, transparency, and compression · MDN: CompressionStream