Compress PNG online

Compress your PNG files online quickly with our free service without losing quality

You have the option to select up to 50 PNG format images by choosing them from your folders or by dragging them directly into the « drag & drop » area. You also have the option to decide the compression level and the output image format before uploading, as yes, you can also perform PNG image conversions.
Once the PNG images are selected, please wait until the compression and/or conversion is complete.

You can then individually adjust the compression quality of the PNG images by clicking on each thumbnail.
Download the compressed images one by one or group them in a ZIP archive.

How to Compress a PNG Image Online?

Using our PNG compressor is completely free and doesn't require the installation of additional software. No registration is required, and there is no watermark or branding on the images. You can freely utilize this tool to compress as many PNG format images as you desire.

  1. Choose the Compression Level you want to apply to your PNG images before starting the online download:
    • Best Quality: Slight compression will be applied to your PNG image to prioritize visual quality above all else!
    • Best Compression: Offering a balance between significant compression and good image quality (this compression level will be applied to your PNG images by default).
    • Custom Compression Level: You can choose a compression level between 1 (maximum compression) and 100 (no compression) and adjust the ideal level to find the balance between image quality and file size.
  2. Upload the PNG Images you want to compress by clicking the « ADD IMAGES » button; you can also drag and drop files into the designated drop area.
  3. Please wait a Moment while your PNG images are processed and compressed according to the previously chosen compression level. Once an image is compressed, you can see the compression level on the thumbnail as well as the percentage of storage space saved after compression for each image. By clicking on a thumbnail, you can also access the weight before and after compression.
  4. Adjust the Compression Level according to your preferences for a specific image. Click on the image and use the quality slider to adjust the level to your liking. When you are satisfied with the compression and image quality, confirm the changes by clicking the « OK » button (you can also adjust compression for all PNG images by changing the compression level and pressing the « REFRESH » button).
  5. Download your PNG images by clicking the « DOWNLOAD ALL IMAGES » button to get a ZIP archive containing all the compressed images once you're satisfied with the compression and quality of each image. Alternatively, you can also download each image individually by clicking the « DOWNLOAD » button located under the corresponding thumbnail.

For additional online PNG image compression, delete the current images by pressing the « DELETE ALL » button and start the process again. With our PNG compression tool, easily and quickly reduce the size of PNG files while maintaining good image quality. An ideal tool for graphic designers, photographers, as well as website administrators looking to reduce their site's loading times without compromising visual quality.

Why Compress a PNG Image?

Compressing a PNG image allows you to reduce the image size while maintaining acceptable quality; There are several reasons to compress a PNG image:

  • More Storage: Reducing the PNG file size allows you to save storage space on your hard drives, USB sticks, servers. PNG compression allows for storing more files, and on devices like smartphones and tablets that have limited storage space with a significant cost for additional space, this is very important!
  • Faster Transfer: Image compression generally reduces the file size without loss of quality, allowing for a faster and more efficient transfer, sharing, or downloading of the image.
  • Avoid Transfer Limitations: Some social media, messaging apps, forums, or websites sometimes have upload limitations on the size of PNG images as well as other formats; compressing your images can help you stay below these limits.
  • Web Optimization: The heavier the images, the longer the web page loading time. By compressing your PNG images, you will significantly improve the loading speed of your web pages thus providing a better user experience for your visitors;
  • Preserve Bandwidth: If you have limited bandwidth or if you pay for the amount of data transferred, compressing PNG images can help you reduce the amount of data you use and thus lower costs as well as improve performance!

In summary, optimizing your PNG images without compromising on quality will help you save, whether it's storage or time!

What is the PNG image format?

A PNG (Portable Network Graphics) image is a digital image format that belongs to bitmap images (made up of pixels) and was created as an alternative to the GIF format (at that time, GIF was a proprietary format, and its compression was under patent), although the PNG format does not support animations like GIFs.

The PNG format is a lossless format suitable for the web!
PNG images can handle transparency (alpha channel) unlike JPEG, which allows for the creation of images with transparent backgrounds. The PNG format is particularly useful for the Web: graphics, logos, icons, drawings, maps, images with solid color areas or any images with transparency zones.

PNG images are supported by all browsers and can be opened and displayed on most computers and mobile devices using standard viewing programs.

Why use the PNG format?

The PNG image format is widely used for these reasons:

  • PNG format compatibility: The PNG format is compatible with all web browsers (Chrome, Mozilla, Safari, Opera..) and is also supported by all operating systems (Linux, Windows, Mac, Android, iOS..) and most, if not all, image processing software.
  • Handles transparency: The PNG format is the most popular format that handles transparency fully, unlike the GIF formats where transparency management is only partial (the WEBP format also handles transparency but is less widespread as it is not supported by all web browsers).
  • PNG and image quality: The PNG format can support millions of colors in addition to its transparency management!
  • Lossless compression: Unlike the JPEG format, which degrades quality with each compression, the PNG format offers lossless compression, allowing an image to be saved and resaved without losing data and maintaining its details.

Advantages and disadvantages of the PNG format

What are the advantages of the PNG format?

  • Easy to use: PNG images are compatible with most web browsers and image editing software; This makes PNG images easily viewable by users regardless of the device and operating system used.
  • Support for transparency: The main reason to use the PNG format over another is its support for transparency (alpha channel), fully while being compatible with all web browsers and image processing software.
  • Space saving: PNG images, once compressed, can take up much less space on your hard drive or web server.
  • Suitable for the web: Several image formats support transparency, such as the TIFF format but this format is not suitable for the web due to its heavy size, contrary to PNG which remains light while allowing good image quality, making it thus a suitable format for the web.
  • Good visual quality: In addition to supporting a wide range of colors, the PNG format uses a lossless compression algorithm, which means that no data/information is lost compared to JPG images.
  • Faster loading time: The reduced weight of the PNG file allows faster loading on websites and mobile applications, providing a better user experience; For webmasters, a faster loading website also allows for better SEO optimization.

What are the disadvantages of the PNG format?

  • Larger file size: For highly detailed images or photos, the PNG format can generate larger files compared to lossy compressed formats like JPG.
  • Animations not supported: The PNG format does not support animations unlike formats such as GIF.
  • Recent EXIF metadata: The EXIF data are metadata generated by smartphones and cameras providing information about the photo or the device that took the photo, whether it's the image dimensions, the file size, the date and time of the photo, the location, as well as the camera settings like the brand, model, focal length. EXIF data is primarily associated with JPEG, TIFF, and RAW formats but since 2017 there has been an extension to the PNG format; These changes being recent, you might lose your EXIF metadata when converting from JPEG to PNG depending on the image processing software used.
  • Longer compression time: Compressing a PNG image can take longer than compressing with lossy formats.
  • Not suitable for some photos: While the choice of the PNG format is wise for icons, graphics, logos, images with solid colors or images with transparent areas, it is not for complex photos or those with many gradients.

How does PNG image compression work?

To reduce the size of a PNG file, lossless compression is used, unlike the JPEG format, which uses lossy compression! Lossless compression allows you to reduce the file size without compromising image quality, allowing you to save and re-save a PNG image without losing data and keeping all its details!
How does it really work?

  1. Preparation: This is an upstream step aimed at reorganizing / transforming the data so that compression can effectively reduce the file size (concretely, instead of directly working on the pixel values of the original image, sequences of more easily exploitable and compressible data are created).
  2. Run-Length Encoding (RLE): This part compresses data where sequences of identical values are found next to each other. If you have a sequence of pixels of the same color, rather than storing each pixel one by one, the format stores the color and the number of times that color appears in sequence. For example, instead of saying blue, blue.. ten times, it simplifies to something like 10xBlue.
  3. DEFLATE Compression: DEFLATE compression is a mix of LZ77 and Huffman encoding, these two methods are combined to minimize the file size of the PNG without losing quality.
    • LZ77: LZ for the inventors Abraham Lempel and Jacob Ziv, and 77 for being invented in 1977. This algorithm searches for redundant data sequences, when it finds a sequence that has already appeared previously, it replaces it with a reference leading to the first occurrence rather than repeating it.
    • Huffman Encoding: This encoding assigns short codes to frequently used elements and longer codes to those that are less frequent (if you make a comparison with a text where you have the word « often » many times, you replace it with « OFT » to reduce the text size).
  4. Finalization: Additional information, metadata, color palettes, and other parameters are added and all this data is then packaged into a single PNG file.

Is compressing PNG images safe?

Our online tool for compressing PNG images is entirely secure, as our servers employ enhanced security measures and operate in an automated manner. This guarantees the confidentiality of your PNG photos and images. No third party has access to the PNG files you upload or compress. When you choose the « Delete All » option or individually delete images by clicking the cross icon next to each file, these are permanently and automatically deleted from our servers. If you don't manually delete your PNG images, they will automatically be removed from our servers after 2 hours.