How to Compress a PNG in Paint

If you need to know how to compress a png in paint, start with a clear expectation: Microsoft Paint has no compression setting. There is no slider, no quality bar, no palette reduction. What Paint does give you is exactly two honest levers: Resize and Save As. Used correctly, they can shrink a PNG by a useful margin. Used alone, they will not touch a photograph that is huge because of sensor noise. That is the real answer to the question Can Microsoft Paint make a PNG smaller, and how? Yes, it can, but only by changing dimensions or switching format. Here is how to work both levers properly and when to admit Paint is not enough.

How to Resize a PNG in Paint

On the Home tab, click Resize (or press Ctrl+W). The dialog gives you two choices: percentage or pixels. Type the new width or height. Paint keeps the aspect ratio locked by default, so changing one dimension updates the other automatically. Uncheck that box only if you intend to stretch or squash the image.

Why Resize Before Saving

File size scales with pixel count. Double the width and you quadruple the data. An image stored at 3000 pixels wide and displayed at 800 carries roughly fourteen times the pixel data anyone will see. Resize down to the display size first. Compressing pixels you are about to discard is wasted work, and the compressor performs better on the smaller image.

What Size to Choose

For a blog image, 1600 pixels on the long edge is plenty. For full-screen use on high-density displays, roughly 2560 pixels covers it. For thumbnails, 400 to 600 is enough. If you need to reduce png size in paint, resize is your fastest win. It costs no quality, only resolution.

Paint Save as JPEG: the Other Lever

Open the image. Go to File > Save as and pick JPEG. That is the large saving available for photographs. A photo stored as PNG is roughly ten times the size of the same photo as JPEG at a quality difference invisible at normal viewing distance. PNG promises exact pixels, so it cannot discard the high-frequency detail that JPEG throws away. Paint’s JPEG export applies that lossy compression automatically.

When JPEG Is the Wrong Answer

JPEG has no alpha channel. If your PNG has transparency, converting to JPEG flattens it onto a solid colour, usually white. JPEG also handles sharp edges badly, producing visible ringing around text and lines. For flat artwork, logos or screenshots with text, JPEG can actually produce a larger file than PNG. Reserve this lever for photographs and images without sharp edges or transparency.

The Real Limit of Paint

Paint has no palette reduction. It cannot drop a truecolour image to 256 colours the way pngquant or TinyPNG does. That means the 70 to 85 per cent saving you can get on a UI screenshot with palette reduction is not possible here. Paint is genuinely enough when you need a quick dimension change or a format switch on a photo. For anything else, you need a tool that can index colours or optimise the compression filter choices. Paint is honest about its limits. Respect them.

What Paint Cannot Do and Why it Matters

PNG compression happens in two stages. First the encoder picks a filter for each row that predicts each pixel from its neighbours and stores the difference. Then DEFLATE compresses the filtered bytes. Flat colour, sharp edges and repeated patterns make the prediction correct, so the differences are mostly zero and zeros compress to almost nothing. Photographic sensor noise makes the prediction wrong nearly every time, giving small random differences that are close to incompressible. That is the whole reason photos are huge as PNG.

Paint does none of this optimisation. It saves the PNG with the default filter and default DEFLATE settings. A lossless tool like optipng or zopflipng can re-run the compression at maximum effort, strip metadata chunks, and save 5 to 15 per cent. Paint leaves all that on the table. If you are publishing a screenshot or a logo, that 5 to 15 per cent is worth getting. Use an online tool or a command-line utility after Paint.

Colour Depth and Metadata

Paint exports truecolour with 8 bits per channel (PNG 24). It cannot export an indexed palette (PNG 8) or reduce bit depth. Palette reduction is the lossy option that rebuilds the image from an adaptive palette of 256, 128 or 64 colours. Two compounding effects shrink the file: each pixel needs 7 or 8 bits instead of 24 or 32, and thousands of near-identical shades collapse into one entry, creating exactly the repetition DEFLATE feeds on. Typical savings on a screenshot are 70 to 85 per cent. Paint cannot do it.

Metadata chunks like colour profiles, comments and creation time can be stripped losslessly. Paint keeps some metadata. A lossless optimiser can remove those chunks and shrink the file further without touching a single pixel.

When Paint is Enough vs When it is Not

How to Save a PNG as JPEG in Paint

Open the image. Go to File > Save as and select JPEG. Paint will prompt you to confirm the format change. Accept it. The file will be dramatically smaller for photographs. For images with flat colour and sharp edges, test the result: JPEG ringing around text can look worse than the original PNG. If the JPEG looks bad, undo and keep the PNG.

This is the only compression lever Paint offers that can match a dedicated tool. Use it when the image is a photograph, when you do not need transparency, and when you are okay with lossy compression. For everything else, resize first, then seek a tool that does palette reduction or lossless optimisation.