Modern smartphones are equipped with powerful cameras capable of creating images with a resolution of tens of megapixels. However, such heavy files take up a lot of space and cause difficulties when sending via instant messengers. Often there is a need to reduce the size of an image or change its physical parameters in order to upload to a specific site.
In this article we will look in detail at how to change the size of a photo in a gallery on Android using built-in system tools and third-party applications. You'll learn about the technicalities of compression, the difference between pixels and kilobytes, and also get step-by-step guide for popular skins.
Built-in editing tools in Google Photos
Most Android users use the standard app Google Photos as the main gallery. This is a handy tool that comes pre-installed on many devices and automatically syncs your photos to the cloud. The functionality of the editor here is quite wide, although directly changing the resolution in pixels can be hidden from the eyes of a beginner.
To change the size, you need to open the photo, click on the button Edit and select the tool Crop. Although this does not directly change the resolution of the sensor, trimming the excess space significantly reduces the resulting file size in megabytes. After cropping, the system will offer to save the changes as a copy, leaving the original untouched.
For more precise control over the weight of the file, new versions of the application have added a compression function when exporting. If you select the option Save a copy after applying the filters, the system may offer a choice of quality. Please note that the compression algorithms in Google Photos are optimized to preserve visual quality while significantly reducing the amount of data.
Use the Free up space feature in Google Photos settings to automatically delete originals if their cloud copies are already compressed service.
Do not forget that after editing it is better to check the file properties. To do this, click on the three dots in the corner of the screen and select Information. There you will see the current resolution and size, which will help you understand the effectiveness of the work done.
Changing the resolution through third-party applications
If the standard gallery does not provide the necessary functions for fine-tuning the resolution, specialized utilities come to the rescue. There are many applications in the store, such as Google Play there are many applications such as Image Size or Photo & Picture Resizerthat allow you to manually set the width and height of the image.
The process of working in such apps is usually intuitive. You select a photo from the gallery, enter the desired pixel values (for example, 1920x1080) or select a reduction percentage. The application recalculates the image matrix and saves the new file.
- 📱 Image Size — allows you to change sizes in pixels, centimeters, inches and percentages while maintaining proportions.
- ✂️ Photo & Picture Resizer —offers ready-made presets for social networks and fast batch resizing.
- 🖼️ QReduce Lite —focuses on reducing the file's weight in kilobytes while maintaining the original resolution.
The reverse process—reducing a large image—takes place with virtually no visible loss to the human eye. Use this property to optimize archives.
Technical aspects: pixels versus file weight
Many users confuse the concepts of image resolution and its weight. Resolution is measured in pixels (for example, 4000x3000) and determines the physical size of the image on the screen. The weight of the file is measured in kilobytes or megabytes and depends on the resolution, as well as on the degree of compression and complexity of the plot.
A photograph of a uniform sky will weigh less than a photograph of a dense forest with the same resolution, thanks to compression algorithms JPEG. Therefore, changing the pixel size does not always guarantee a proportional reduction in weight. Sometimes you need to use special compression algorithms.
| Parameter | Unit of measurement | Impact on quality | Where to change |
|---|---|---|---|
| Resolution | Pixels (px) | High (detail) | Editors, crop |
| File weight | Kilobytes (KB) | Medium (compression artifacts) | Converters, compression |
| Format | File type | Depends on codec | Save as.. |
| Color depth | Bit per channel | Color rendition | Prof. editors |
When preparing a photo for sending to instant messengers, it is often necessary to reduce the weight of the file so that it passes the limitations of the service. In this case, changing the pixel resolution is just one way to achieve the goal.
Batch processing of images in the gallery
When you need to resize not just one, but a dozen images, manual processing becomes ineffective. Some advanced galleries, for example Gallery Go or third-party file managers, support batch editing.
To start the process, you need to select several files with a long tap, then select the option Resize or Compressin the menu. The system will apply the selected parameters to all marked objects simultaneously. This saves time and ensures consistent results.
⚠️ Attention: When batch resizing, make sure you select the exact photos you want to process. It can be difficult to cancel a mass action for each file separately.
If the built-in tools of your smartphone do not support group operation, it is advisable to use applications like Batch Resize. They allow you to create a settings profile and apply it to an entire folder of images in a few seconds.
☑️ Preparing for batch processing
Features of working in different Android shells
The interface and capabilities of the standard gallery highly depend on the smartphone manufacturer. Shells from Samsung, Xiaomi and Huawei have their own unique features in the editing menu.
On devices Samsung with the One UI shell, the resizing function is often hidden in the menu for creating a collage or GIF animation, if there is no direct button. At the same time, Xiaomi (MIUI) often provides direct access to changing the resolution in the menu More when editing.
- 🔹 Samsung One UI: Often requires using the "Create" mode to indirectly change parameters.
- 🔹 Xiaomi MIUI: It has a built-in tool for changing the resolution in the editing menu.
- 🔹 Stock Android: Relies on the capabilities of the Google Photos application.
Users of pure Android or devices with rare firmware are recommended not to look for hidden menus, but to immediately install a lightweight editor. This will save you from unnecessary clicks and incomprehensible interface solutions.
Why do different phones have different menus?
Android manufacturers modify the source code of the system, adding their own interface layers. This allows them to stand out in the market, but creates a fragmented user experience.
Preserving quality when resizing
The main problem when reducing the size of a photo is the loss of detail and the appearance of compression artifacts. To minimize damage, it is important to select the export parameters correctly. You should not strive for an extremely small file weight if image clarity is important.
Use the format PNGif the image contains text, graphics, or clear boundaries of objects. This format uses lossless compression, although the resulting file can be larger than JPEG. For photographs of landscapes and people, the optimal quality remains JPEG with a quality of about 80-90%.
⚠️ Attention: Avoid repeatedly saving the same JPEG file. Each save accumulates compression errors, irreversibly degrading the image.
Modern algorithms in converter applications often use neural networks to improve the image after reduction. This allows you to maintain sharp edges even under strong compression. Look for options like “Smart Resize” or “AI Enhance” in the settings.
Golden rule: Always store the original photo in a separate folder or cloud. Use the modified copy for specific tasks, leaving the original untouched.
Frequently asked questions and problems (FAQ)
Why did the photo become blurry after resizing?
Blurry occurs if you reduced the resolution and then tried to enlarge the image again, or if the JPEG compression level was too high. Pixel removal algorithms are irreversible.
How to resize a photo without installing applications?
You can use online services in your phone browser (for example, iloveimg or resizeimage.net). Also, some instant messengers (Telegram) allow you to send a photo as a file without compression or with a choice of size before sending.
What is the difference between DPI and resolution in pixels?
Resolution (pixels) is the number of pixels in width and height. DPI (dots per inch) is the print density. For a smartphone screen, it is the number of pixels that is important; DPI only affects printing on paper.
Is it possible to change the size of a photo in the iPhone gallery in the same way?
On iOS, the standard gallery does not allow you to change the resolution directly. Only trimming is available there. Changing pixel sizes on iPhone also requires third-party apps or Shortcuts.