Free online PNG optimizer

Optimize PNG. Keep the quality.

Compress PNG files by up to 80%, resize in bulk and download everything as a ZIP. Transparency stays intact. No signup, no watermark, completely free.

80% size reduction
50MB max file size
100% free forever

Drop your PNG files here

or click to select files from your computer

Up to 10 PNG files  |  max 50 MB each  |  ZIP download for 3+ files

Quality: Balanced (75%) - Original size

What is PNG Compression?

PNG (Portable Network Graphics) is the most widely used lossless image format on the web, but raw PNG files can be unnecessarily large. OptimizePNG applies smart lossy compression that reduces file sizes by up to 80% while keeping images looking virtually identical - meaning faster page loads, better Core Web Vitals scores, and lower bandwidth costs.

Optimized PNGs preserve full alpha transparency and work in every modern browser and editor. Whether you are a developer optimizing web assets, a designer preparing graphics, or a blogger compressing images for faster publishing - OptimizePNG handles it with zero configuration.

Why Compress PNG Files?

Large PNG files slow down your website and hurt search rankings. Google uses page speed as a direct ranking factor, and unoptimized images are one of the biggest performance bottlenecks. Compressing your PNGs dramatically improves load times without sacrificing visual quality - and also reduces storage and bandwidth costs.

Need to go further? Convert PNG to WebP for even smaller file sizes, or convert PNG to JPG when you do not need transparency. For 256-color images, try our PNG to 8-Bit converter.

How to Compress PNG Files Online - Step by Step

  1. Drag and drop up to 10 PNG files of up to 50 MB each into the upload area above, or click "Browse Files" to select them from your computer or device.
  2. Optionally click "Customize Settings" to choose a quality preset (Max, High, Balanced, Small, Tiny) or set a custom resize dimension using a quick preset or manual width/height input.
  3. Three files compress at a time and the rest start automatically as slots free up - watch the progress bars and thumbnails update in real time.
  4. Download compressed files individually with the Download button, or click "Download ZIP" when you have 3 or more completed files to save them all at once.

PNG Optimizer vs Other Ways to Shrink a PNG

There is more than one way to make a PNG smaller. Here is how they compare, so you can pick the right one - or stack two of them.

MethodTypical savingKeeps transparencyBest for
Smart lossy optimization (this tool)50-80%YesScreenshots, logos, UI, illustrations
Lossless recompression only5-25%YesPixel-exact assets, medical or print archives
8-bit / 256-color palette60-85%YesFlat graphics, icons, pixel art
Resize to display sizeUp to 90%+YesOversized exports and camera-sized images
Convert to WebP25-50% vs PNGYesWebsites that control their image formats
Convert to JPG60-90% for photosNoPhotos with no transparent areas

Savings depend on the image - flat colors shrink the most, noisy photos the least. Want the full walkthrough? Read how to reduce PNG file size: 7 methods that work.

How the PNG Optimizer Works

Most PNGs store millions of possible colors, yet use only a few thousand. The optimizer finds the colors your image really needs and rebuilds the palette around them.

It uses pngquant, the open-source quantizer behind many popular image tools, and re-encodes the file around that compact palette. The result is still a standard PNG - same dimensions, same transparency, a fraction of the bytes.

Tips for Smaller PNG Files

  • Export at the size you display - a 4000 px image shown at 800 px wastes 96% of its pixels.
  • Hit an exact limit with Compress to Size (e.g. 100 KB or 1 MB).
  • Strip hidden camera and editor data with the Metadata Remover.
  • Logos and icons? 8-bit usually beats everything else.

Batch Compression & ZIP Download

Upload up to 10 PNG files at once, each as large as 50 MB. Three upload at a time so nothing stalls on a slow connection, and the queue advances by itself. When you have 3 or more completed files, the "Download ZIP" button appears - giving you a single archive with all compressed images plus a summary file.

All processing happens securely on our servers. Your original files are never shared and are automatically deleted after processing.

Frequently Asked Questions

OptimizePNG uses smart lossy compression that is virtually indistinguishable from the original. It reduces colors intelligently while preserving visual appearance. For most images, the difference is imperceptible even at close zoom levels. We recommend the "Balanced" preset for the best results on web images.

Yes. Your uploaded files are processed on our secure server and automatically deleted within 2 hours. We do not store, share, or analyze your images. No account or signup is required. Your privacy is fully protected.

Each PNG file can be up to 50 MB in size - far more than most free compressors allow. You can upload and compress up to 10 files at once for batch processing. When you have 3 or more compressed files, you can download them all as a single ZIP archive with one click.

Yes. OptimizePNG accepts PNG files up to 50 MB each, so full-page screenshots, scans, game textures, and high-resolution exports are all handled. Large files naturally take longer - three upload at a time and the rest wait their turn, so keep the tab open until the Download button appears. If a big file keeps failing, please contact our support team and we'll take a look.

Absolutely. OptimizePNG fully preserves alpha transparency. The compressed PNG output maintains all transparency information, making it perfect for logos, icons, and web graphics that need transparent backgrounds. You can also convert PNG to ICO while keeping transparency intact.

Max (95%) - barely any compression, best for print or archiving. High (85%) - excellent quality with noticeable size reduction. Balanced (75%) - recommended for most web images. Small (60%) - strong compression for thumbnails or previews. Tiny (40%) - maximum compression, ideal when file size is the top priority.

Compress PNG reduces file size using smart lossy compression while preserving color depth and full transparency. PNG to 8-Bit specifically converts your image to an indexed 8-bit palette (maximum 256 colors), which is ideal for graphics, logos, and icons with limited colors. For full-color photos, use the Compress PNG tool instead.

Run it through the PNG optimizer above first - smart color quantization removes 50-80% of the size of most screenshots, logos and UI graphics with no visible change. Still too big? Resize it to the size it is actually displayed at, strip metadata, or convert photos to WebP. Our PNG size guide covers every option.

Yes - "minify PNG", "optimize PNG" and "compress PNG" all describe the same goal: a smaller file that looks the same. The output is still a normal PNG, so it opens in every browser, editor and CMS and keeps its transparency.

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