How to Compress an Image?

When working with digital images, such function as compression (optimization) is often required in many cases. As a result, the weight of the photo is reduced, which makes it convenient to send the file by e-mail or post it on a web resource. The difference between the original and the modified photo when compressed can be completely invisible on a computer monitor. But it will be visible when printing the image. Therefore, it’s very important to know and understand how to compress an image correctly to preserve the quality, clarity, and attractiveness of the image.

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Why is Image Compression Important?

Many users may ask the question, in which cases there is a need for photo compression.

Due to the competent optimization of images and reducing their weight, you can get such advantages:

      • Reduce the loading time of the site pages and speed up the display of images.
      • Free up memory in your phone/computer by almost 80%.
      • Quickly and easily share images via email, social networks, and more.

The need to compress photos most often appears when they need to be uploaded to the site. After all, according to research, if a site page loads for more than 3 seconds, visitors close it and go to competitors. And too heavy pictures significantly affect this factor of the site.

Modern users have become more spoiled lately. They want to find what's necessary without spending too much time and effort. Therefore, the response of the resource cannot be long.

What happens if you don't compress the images before posting them on the site:

  1. Problems with page loading and conversion drop. Even users who have high-speed Internet will not be able to load sites with heavy photos quickly. Accordingly, the entire page will take a long time to load. As a result, there will be fewer visitors, the conversion rate will worsen and the company's revenue will decrease.
  2. Waste of Internet traffic from users. No one will like it if downloading a heavy image takes precious bytes of the Internet and «eat» traffic. So, image compression is the right solution in such a situation.

Some sites have restrictions on the size of uploaded photos. This should also be taken into account. If the weight of the image is greater, then it will not be possible to load it. Then the question about compression image files will be more relevant than ever.

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How Does Compress an Image Function?

The image compression is to process the file. This allows you to reduce its weight. At the same time, the issue of quality remains important. After all, losses should be minimal. Various image optimization algorithms have approximately the same essence. The service data is removed from the file. This may be the name of the program where the image or repeating colors were saved. After optimization, the image remains the same as the original one. There is nothing visually changes in principle, but the weight of the file itself becomes much less.

If you use the tools to compress photo correctly, then the image size can be reduced by 70-90%.

There are two main ways to compress photos:

      The compression photos without loss of quality. In this case, the process is similar to creating a ZIP file. Duplicate digital image data is compressed, but the quality is not lost when opened or extracted.
      The compression photos with loss of quality. In this variant, some information is deleted during compression, which significantly reduces the weight of the image. But when a person opens it, changes it, saves it again, the quality deteriorates significantly.
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Some services take into account certain aspects of the human visual system. For example, when compressing JPEG images, it’s taken into account that the visual system gives priority to more homogeneous visual information, and sends secondary details to the background. Therefore, when optimizing, they retain more information about brightness than about color. Changes in light intensity have a great effect on the human eye.

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Where Can You Compress Photos?

You can compress an image size using various services and programs. Even standard system programs on Windows allow you to reduce the weight of images. Therefore, professional skills will not be required to perform such a task.

However, our Watermarkly online image compressor will allow you to simplify the task as much as possible. You do not need to download and install it on your computer, search for drivers and perform other manipulations.

If you do not compress images yourself in special services, the site can automatically optimize them. In this case, the quality may deteriorate significantly and the image will not be visually attractive. Therefore, before uploading photos to a website or social networks, reduce their weight yourself in a special application to preserve the quality.

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How to Compress an Image in Our Image Compressor

Watermarkly web application works with three common image formats:

      • JPEG;
      • PNG;
      • GIF.

Most JPEG images can be compressed without significant loss of quality.

Our service optimizes the file structure and does not waste space to save redundant information.

As for PNG and GIF, when optimizing the image, the quality inevitably deteriorates. Fortunately, our program does everything possible to ensure that the resulting image remains attractive.

Now we’ll tell you how to compress an image file:

  1. Go to the Compress section.
  2. Upload one or more images by dragging files from a folder on your computer or choose another option: upload from your computer, Google Drive, Google Photos, or Dropbox. In the last three cases, you will need to permit to access files in the cloud storage. select images to compress
  3. Click «Compress image» and select the quality you want to get after processing the photo. select quality of compressed photo

Our web application offers three quality options for compressing an image:

  1. Better Quality. In this mode, our online tool will do everything to ensure that the quality of optimized photos remains as high as possible. In other words, it will compress an image without losing quality.
  2. Smaller Size. This mode is suitable if the image quality is not in the first place.
  3. Specific File Size. In this case, you can independently specify the required number of kilobytes for image compression. That is, the final weight of the image will depend on you.

With the first and second options, the weight of the file can be seen only after selecting one of the items.

Our service Watermarkly does everything possible to make the images look attractive and not inferior to the originals when compressing an image size. At the same time, the system reduces the image to a certain size in kilobytes.

How to Compress an Image Size in a Smartphone

If the images that need to be optimized are in the phone's memory and you need to urgently reduce their weight, you can work in the application through your smartphone. Just open our website and go to the «compression» tab. The visual and functional part of the application in the phone will not differ from the desktop version. You will also need to upload a photo from a suitable medium and specify the output quality format. Images can be saved in the phone's memory or one of the cloud services provided.

Our web application allows you to compress an image on Mac, and do it on Windows devices. In addition, our site is optimized to work through a smartphone. So, owners of iPhones and gadgets with Android OS can easily compress photos from anywhere and have access to the necessary files. The only condition for working with the tool is the availability of Internet access.

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Advantages of Watermarkly Image Compressor

We can highlight the following advantages of working in our application:

  1. The online tool can compress files in three formats simultaneously: JPEG, PNG, and GIF. Compressed images get the same size as modern formats: HEIC and WEBP. When using the free version of the app, you can download up to 10 images at the same time. Paid updates provide more features – read about them on the page.
  2. Watermarkly is a web application that does not need to be installed on a computer. Just open your favorite Internet browser, visit our website and start working on photos. There is no risk of downloading a malicious file to your computer with us, no need to waste time installing and activating the free version. All functions are fully accessible to every user.
  3. You can compress an image with us quickly and without queues. Each client uses the tool independently of each other’s, there is no waiting period for processing another person's photo. This significantly reduces the time spent working with images.
  4. User data is not stored on our servers, so they remain yours until the end. Therefore, we can guarantee the complete confidentiality of the images of all visitors to the site.
  5. The application provides more features than just compressing an image. With the help of our service, you can easily add watermarks to pictures, crop photos according to the set aspect ratio or according to the circle/rectangle pattern, resize the picture, or add a logo.
free photo compressor online

You don't need the skills of a graphic designer to work in the application. All step-by-step actions are primitively simple and easy, so you will not have any difficulties.

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JPEG, PNG, GIF. What Image Format Should Be Using and When?

As a rule, people use three main image formats:


The format displays millions of colors, suitable for images with a high level of compressed photos. When the weight is reduced, the files are well preserved, but in general, the appearance of the image depends entirely on the compression level. JPEG format is not suitable for images with a small amount of color data (for example, screen screenshots).


This format also supports many colors, but it is more advantageous in a photo with fewer color data. PNG format is not suitable for high-quality photos, because they lose JPEG in volume. PNG supports transparency, thanks to which it is successfully used when creating a logo, icons, and various graphic elements.


This format has more specific applications. In most cases, it is used for animated images. It is more difficult to optimize such files because the result is not always as good as when working with JPEG and PNG.

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Answers to Frequently Asked Questions

We have prepared several answers to the most popular questions that users have on the topic of how to compress an image. We hope you will find the necessary information here. If you have any questions about the operation of our application, you can contact our support service.

How to compress image size in jpeg format?

Our web application allows you to optimize JPEG photos to reduce their weight. The process is quite simple. You need to upload images and click the «compress» button. Then the service will ask you to choose the appropriate image quality option. When working with customer photos, our system tries to do its best to keep the image quality as close to the original as possible.

For what purpose are photos compressed?

It is necessary to reduce the weight of the images so that they do not affect the loading speed of the page on which they are placed. In addition, some websites and social networks place restrictions on the weight of the file to upload to their platform. In this case, too voluminous photos will not be uploaded and you will need to compress an image. This process will not take you much time if you use our Watermarkly application.

How to compress an image without losing quality?

Don’t rely on the fact that when optimizing images, you will be able to fully preserve their original quality. Compression involves the removal of certain information, which entails consequences in the form of changes in the characteristics of the image. However, you can use editors that allow you to compress images and choose the best quality when saving. There is a function in our application. In this case, the system reduces the weight of the photo but leaves the best possible quality.

How deep can JPEG be compressed?

Some JPEG images can be reduced by 50-100 bytes. In order not to lose image quality, it is necessary to compress it by 10-40%. Remember that the compressed version of JPEG photos contains less information about the file. Because of this, the quality of some elements (sharpness, color, contrast) may decrease.

Do I need to compress photos to send them by email?

Yes, you do. Each mail service sets its limits on the size of attachment files that can be sent to other people. If you want to send photos that exceed the set limit, then be sure to optimize them in advance. There will be no difficulties with sending a message in this case, and the task will be completed in a matter of minutes.

How to compress an image on iPhone?

It is not necessary to download special applications to optimize images on iPhone and Android gadgets. Our online service has an adapted mobile version and allows you to work on the site through a mobile browser. In this case, the algorithm of action for compressing images will be the same as in a computer. You just need to upload a photo and choose the appropriate quality for the downloaded files.

Why do I compress photos if I don't have a website?

Our tool allows you to reduce the weight of images so that you can free up memory in your device, share them on various platforms and not worry about the fact that restrictions on the weight of images will not allow you to do this.

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Compress Photos in a Few Minutes with Watermarkly

We have told you why you need to compress an image and how to do it easily on our website. If you urgently need to optimize photos, just log in to the web application. All functions are available for free and online. If you need to process more than 10 photos at once, consider purchasing updates that will further expand your ability to work with pictures on our website.

Improve your images with Watermarkly qualitatively and do not waste precious time installing the program on your computer. Working on image optimization with us will be quick and easy.