How to Compress PNG Images Online
Watermarkly makes it easy to reduce PNG file size online in just a few steps. Upload your files, choose the compression mode that fits your goal, and download optimized PNG images when processing is complete.
- Open the PNG compressor. Go to the app window to start compressing your PNG images.
- Upload your PNG files. Click the blue Select Images button to upload PNG files from your device, Dropbox, Google Drive, or Google Photos. You can also drag and drop images from a folder on your computer. If you import files from cloud storage, allow Watermarkly to access the selected files. To upload more images, click Add Images. To remove all imported files from the app, click Clear.
- Choose your compression settings. Once your PNG files are uploaded, the compression settings will appear automatically. Choose how you want to reduce the size of your PNG files.
- Choose one of three PNG compression options:
- Better quality. Choose this option if image quality is your priority. It uses lossless PNG compression to reduce file size without changing the image data. The compressed PNG usually looks identical to the source file, although the size reduction may be moderate.
- Smaller size. Choose this option if you want to make PNG files significantly smaller. This mode uses lossy PNG compression by reducing the number of colors in the image. For example, a 24-bit RGB PNG or a 32-bit RGBA PNG with transparency can contain millions of possible colors, while the compressed version may use a reduced palette of up to 256 colors. This can noticeably reduce PNG file size while keeping transparent areas intact.
- Specific file size. Choose this option if you need to reduce PNG to a specific size in KB or MB. Enter your target file size, and Watermarkly will try to create a compressed PNG that gets as close to that limit as possible. This is useful when you need to meet upload requirements for websites, forms, email attachments, marketplaces, or online platforms.
- Compress and download your PNGs. Click the Compress Images button. Watermarkly will process your PNG files and show how much space you saved in percentages and kilobytes. Once the compression is complete, download the optimized PNG images to your device or cloud storage.
Why Use Watermarkly’s PNG Compressor?
Watermarkly helps you reduce PNG file size with flexible compression settings, batch processing, and convenient cloud import.
Batch Uploads and Downloads
PNG files are often used in sets: product icons, interface elements, logos, screenshots, or website graphics. Watermarkly lets you compress many PNG images at once, so you don’t have to process them one by one.
If your PNGs are already stored in the cloud, you don’t need to download them to your computer first. Add the files directly to the PNG compressor, process them together, and download the optimized PNGs individually or as a batch.
There are no ads to wait through, no unnecessary registration steps, and no hidden fees.
No File Size Limits or Watermarks
Watermarkly doesn’t limit the size of the PNG files you upload or the number of images you can process in one session. This is useful when you need to compress large PNG screenshots, design exports, or multiple transparent graphics at the same time.
The compressed PNG files are not watermarked, so you can use them right away on your website, in an online store, in a form, in a presentation, or anywhere else you need smaller image files.
Control Over PNG Compression Quality
Watermarkly’s PNG compressor supports both lossless and lossy PNG compression, so you can choose how much you want to reduce file size and how close the result should stay to the source image.
Use lossless compression when quality matters most and you want the compressed PNG to look virtually unchanged. Choose lossy compression when your priority is to make the PNG file much smaller, even if that means simplifying the color palette. This gives you flexible control over the balance between image quality and file size before compression starts.
Private Browser-Based Processing
Your PNG images are processed locally in your browser. This means they are not uploaded to Watermarkly’s servers during compression, and no one from our side can view or access your files.
Your source images also stay unchanged. Watermarkly creates compressed copies of your PNG files, so you can compare the results and save the optimized versions next to the originals.
More Ways to Reduce PNG File Size
If your PNG file is still too large after compression, you can try other ways to make it smaller while keeping the image usable. For example, you can resize PNG images to reduce their dimensions or convert PNG to WebP for a lighter web-friendly format with Watermarkly’s free image optimization tools.
How Does PNG Compression Work?
PNG compression works differently from JPEG compression. JPEG is mostly used for photos and usually makes files smaller by removing some visual detail.
PNG is designed for images where clean edges, readable text, flat colors, and transparency matter, so the goal is different: make the file lighter without making it look messy.
A PNG file stores image data in a way that can be compressed without changing how the image looks. Before saving the file, PNG prepares the pixel data so repeated patterns become easier to find. Then it applies a compression method similar to the one used in ZIP files.
Some PNG compressors can go further by simplifying color information before the file is saved. Instead of keeping every tiny color difference, the compressor groups similar colors together and keeps the ones that matter most visually. This process is called color quantization. It can make PNG files much smaller, especially when the image contains logos, interface elements, text, or flat-color graphics.
Compression tools may also remove unnecessary metadata, such as software information, timestamps, or other hidden data that is not needed to display the image. This reduces file size without affecting the visible picture.
In simple terms, PNG compression makes the file smaller by finding patterns, storing color information more efficiently, and removing data that the image does not need. The result is a lighter PNG that is easier to upload, share, and use online.
How to Choose the Best Way to Reduce PNG File Size
Different PNG images need different optimization methods. A logo, a screenshot, and a large website graphic should not always be compressed the same way.
To get the best result, choose the method that reduces file size without making the image look worse than necessary.
For logos, icons, UI elements, and screenshots, start with lossless PNG compression. These images often contain sharp lines, small text, and flat colors, so aggressive lossy compression may make edges look fuzzy or create visible color banding.
For large illustrations or decorative website graphics, lossy PNG compression can work well if the visual difference is hard to notice. This can significantly reduce PNG file size while keeping the image suitable for web pages, landing pages, and online stores.
For photos, PNG is usually not the best format. PNG files for photographs are often much larger than necessary. If the image does not need transparency, convert it to JPEG, WebP, or AVIF instead.
For transparent images, keep PNG if you need broad compatibility and clean transparency. You can also consider WebP or AVIF if your website supports them, but avoid JPEG because it does not support transparent backgrounds.
For better website performance, don’t rely on compression alone. Resize oversized PNG images and create different versions for different screen widths, so mobile users do not have to load the same large file as desktop users.
Frequently Asked Questions
Here are answers to common questions about PNG compression, image quality, transparent backgrounds, and reducing PNG file size online.
Will PNG compression affect image quality?
It depends on the compression mode you choose. Lossless PNG compression reduces file size without changing the image data, so the compressed PNG usually looks identical to the source file. Lossy PNG compression can make the file much smaller, but it may slightly change colors or fine details because the image data is simplified before saving.
Can I reduce PNG size without losing transparency?
Yes. Watermarkly’s PNG compressor keeps transparent backgrounds intact. This is important for logos, icons, product images, stickers, interface elements, and other PNG files that need transparent areas to display correctly.
How can I make a PNG image smaller?
You can make a PNG image smaller by compressing it, resizing it, or converting it to a lighter format. Start by using Watermarkly’s PNG compressor to reduce file size online. Upload your PNG files from your device or cloud storage, choose the compression option that fits your goal, and download the optimized images when processing is complete.
Can I reduce PNG file size for free?
Yes. Watermarkly’s PNG compressor is free to use. You can compress multiple PNG images at the same time, and the optimized files will not have added watermarks, text, or logos.
Why is my PNG file so large?
PNG files can be large because they often store detailed image data, transparent areas, and many colors. Screenshots, design exports, large graphics, and high-resolution images can become especially heavy. Compression, resizing, and color optimization can help reduce PNG file size.
Is PNG better than JPEG for compression?
PNG and JPEG are best for different tasks. PNG is usually better for graphics, screenshots, logos, icons, and images that need transparency. JPEG is usually better for photos because it can make photographic images much smaller. If your image does not need transparency, WebP or AVIF may also be a good option for web use.
Does PNG compression remove metadata?
Some PNG compression methods can remove unnecessary metadata, such as software information, timestamps, or hidden technical data that is not needed to display the image. Removing metadata can reduce file size without changing the visible picture.
In Watermarkly’s PNG compressor, you can choose whether to keep or remove metadata before compression. Keep metadata if you need file information to stay attached to the image, or remove it if your priority is a smaller PNG file and cleaner output.