Overview
Introduction
This tool shrinks a PNG's download size by reducing its resolution, entirely in your browser.
Because file size scales roughly with pixel count, cutting the dimensions is often the fastest way to make a PNG dramatically smaller.
What Is PNG File Size Reducer?
A client-side resolution downscaler that reads an uploaded PNG's pixel data and resamples it to a smaller width and height using nearest-neighbor interpolation, the same fast algorithm the site's other resize tools use.
Unlike a general-purpose resizer, this tool frames the control as a single 'how much smaller' percentage aimed specifically at reducing file weight.
How PNG File Size Reducer Works
You choose a scale percentage from 1 to 100; the tool multiplies the original width and height by that percentage (rounding to whole pixels, with a floor of 1px) and resamples every output pixel from its nearest source pixel.
The tool also reports the percentage reduction in total pixel count, since that's a good proxy for how much smaller the resulting file will be.
When To Use PNG File Size Reducer
Use it whenever a PNG's dimensions are larger than needed for where it will actually be displayed, such as a hero image sized for print resolution but shown at web resolution.
It's the right first step when a PNG's file size is the problem and its pixel dimensions have obvious headroom to shrink.
Often used alongside PNG Compressor and PNG Resizer.
Features
Advantages
- Runs entirely client-side; the uploaded image is never sent to a server.
- Usually the single most effective way to reduce a PNG's byte size.
- Reports the percentage pixel-count reduction so you can gauge the impact before downloading.
Limitations
- Downscaling is destructive: fine detail lost during resampling can't be recovered later by re-upscaling.
- Nearest-neighbor resampling can look aliased on images with fine diagonal lines or text compared to a smoother (bicubic) algorithm.
Examples
Best Practices & Notes
Best Practices
- Scale down only as much as the image's final display size requires; there's no benefit to a resolution far larger than where it will be shown.
- Check the resulting dimensions in the preview before downloading, especially at very small scale percentages.
Developer Notes
The lib function reuses the shared resizeNearest helper (also used by png-resizer) rather than reimplementing resampling, and additionally reports the before/after pixel counts and percentage reduction, purely as an informational estimate of the file-size impact.
PNG File Size Reducer Use Cases
- Shrinking an oversized PNG before using it as a web asset
- Generating a smaller preview or thumbnail version of an image
- Cutting bandwidth costs for image-heavy pages
Common Mistakes
- Reducing resolution when the real problem is color complexity — try the PNG Compressor first if dimensions are already reasonable.
- Scaling down so aggressively that the image becomes illegible at its intended display size.
Tips
- Combine with the PNG Compressor for maximum file-size savings: downscale first, then quantize colors.
- If you need an exact target width or height rather than a percentage, use the PNG Resizer instead.