Do files on your smartphone take up too much space? High-resolution photos, multi-megabyte PDF contracts, or PowerPoint presentations can quickly fill up your device's internal memory. This problem is especially relevant for budget models with 8–32 GB of storage, where every megabyte counts. Fortunately, you can reduce the size of documents by Android without a computer - right from your phone screen.

In this article you will find proven compression methods for different types of files: from office documents (.docx, .xlsx, .pptx) to scans and photographs. We will look at both built-in tools Android 12–14and specialized applications with advanced compression algorithms. We will pay special attention preserving the readability of the text and minimal loss of image quality —after all, the main thing is not just to reduce the weight of the file, but to do it competently.

1. Compressing PDF documents: from scans to contracts

Format .pdf is widely used for storing scans, contracts and e-books, but often such files take up an unreasonably large amount of space. The main reasons: high resolution images inside the PDF, redundant metadata or unoptimized fonts. On Android there are several ways to reduce their size.

The easiest method is to use the application Adobe Acrobat Reader (free version available in Google Play). After installation, open the PDF file through the app, click on the ⋮ icon (three dots) in the upper right corner and select Compress PDF. The system will offer two options: High quality (~30% reduction) and Smaller size (up to 70% savings). For text documents without images, you can safely choose the second option - quality loss will be minimal.

  • 📱 Adobe Acrobat Reader — built-in compression function with preview of the result.
  • 🔍 PDF Compressor — allows you to set the DPI for images inside PDF (optimally: 150–200 DPI for documents).
  • 🌐 Online services (for example, Smallpdf or iLovePDF) - convenient for one-time tasks, but require uploading a file to the server.
⚠️ Attention: When compressing PDF with images (for example, scans of a passport) through online services, check the final file for artifacts. Some tools aggressively reduce resolution, making small text unreadable.
📊 What type of PDF do you most often compress?
Document scans
Books/textbooks
Contracts/agreements
Presentations
Other

2. Optimizing Word and Excel documents

Files .docx and .xlsx from Microsoft Office often contain hidden data: edit versions, styles, unused images, or embedded fonts. Even an empty document can weigh several megabytes. To reduce their size by Android, use the mobile version Microsoft Word/Excel or alternative editors.

Instructions for Microsoft Office:

  1. Open the file in the application Word or Excel.
  2. Go to File → Details → Reduce file size.
  3. Select option Remove personal data and unused styles.
  4. Save the file under a new name (for example, adding "_compressed").

For deeper optimization, use the application WPS Office —it offers the "Compress Document" function with adjustable compression level (from "Lossless" to "Maximum").

Application Max. compression Supported formats Features
Microsoft Office up to 40% .docx, .xlsx, .pptx Removes metadata, but does not compress images inside the file.
WPS Office up to 60% .doc, .xls, .ppt, .pdf Allows you to select the compression level for images.
OnlyOffice up to 50% .odt, .ods, .docx Supports open formats, but does not compress well .xlsx.

If a document contains many images (for example, a report with graphs), export it to .pdf via File → Export, and then compress the resulting PDF using one of the methods from the previous section. This often gives better results than direct compression in .docx.

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Before compression, remove unnecessary pages, empty lines and headers from the document - this will additionally reduce the final file size by 10-20%.

3. Reducing the size of images and scans

Photos from a smartphone camera (especially in .HEIC or .RAWformat) and scans of documents can take up 5-10 MB each. To optimize them, both built-in tools and third-party applications are suitable. The main rule: for Android Both built-in tools and third-party applications are suitable. The main rule: for documents (passports, checks) permission is sufficient 150–200 DPI, and for photos — 72–100 DPI (if they are not intended for printing).

Compression methods:

  • 📸 Google Photos: automatically compresses images when uploading to the cloud (the "High Quality" option instead "Original"). Suitable for backups, but not for official documents.
  • 🔧 Photo & Picture Resizer: allows you to set precise parameters (resolution, JPEG quality, cropping). For example, for a passport scan, set the width 1200 px and quality 80%.
  • 🖼️ PicsArt or Snapseed: in addition to compression, they allow you to trim unnecessary fields (for example, black edges of scans).

⚠️ Attention: When compressing scans for government services (for example, for Gosuslug or banks) check the format requirements. Some organizations only accept files with a resolution of at least 300 DPI and in the format .jpg or .png.

For batch processing (for example, compressing 50 photos at a time), use Batch Image Resizer. The application supports preset settings: set the parameters once (for example, width 1920 px, quality 75%), and then apply them to all files in the folder.

How to check the DPI of an image on Android?

Open the file in the application Photo EXIF Editor (free on Google Play). Go to the "EXIF" tab - there will be a "Resolution" line with the current DPI value. For documents, 150–200 DPI is optimal, for web images - 72 DPI.

4. Format conversion: when compression doesn't help

Sometimes you can reduce the file size not by compression, but by converting to a more efficient format. For example:

  • .tiff → .jpg (saving up to 90% space).
  • .bmp → .png (maintains transparency, but weighs 3–5 times less).
  • .doc → .docx (the new format takes up 30–50% less space).
  • .wav → .mp3 (for audio recordings).

For conversion to Android suitable for:

  • 📑 File Converter —supports 100+ formats, works offline.
  • 🎵 Audio Converter —optimized for compressing music and voice recordings.
  • 📄 Zamzar (online)—convenient for rare formats (for example, .odt → .pdf).

Example: a 50 MB file after conversion to .tiff 50 MB after conversion to .jpg quality will weigh ~2-3 MB However, remember that 90% will weigh ~2–3 MB. However, remember that .jpg does not support transparency - for logos or screenshots with. select alpha channel .png.

Make sure that the source file is not password protected

Check the final format for compatibility with the target device/service

Make a backup copy of the original

Select the optimal quality (for example, 80% for JPEG)-->

5. Archiving files: ZIP, RAR, 7z

If a document consists of several files (for example, a folder with photos or a project in Figma), they can be archived. built-in and third-party tools. The main difference between the formats: Android There are built-in and third-party tools for this. The main difference between the formats:

  • .zip - universal, opens on any device, but the compression is average.
  • .rar - compresses multimedia better, but requires installation WinRAR or RAR for unpacking.
  • .7z —maximum compression (20–30% more efficient .zip), but not all apps support it.

Instructions for the built-in archiver (available at Android 11+):

  1. Open Google files (or any other file manager).
  2. Select the required files, click ⋮ → Compress.
  3. Select format (.zip or .7z) and compression level (for example, "Maximum").
  4. Wait for completion - the archive will appear in the same folder.

For advanced settings (for example, partitioning into volumes or encryption) use ZArchiver or RAR.

⚠️ Attention: Archives with a password (encrypted) may not open on some devices due to security policy restrictions. Before sending such a file, check it on another smartphone.

6. Clearing metadata: EXIF, comments, change history

Any file contains service information that increases its size. For example:

  • Photos: data EXIF (camera model, geolocation, shooting settings).
  • Word/Excel documents: editing history, comments, hidden layers.
  • PDF: bookmarks, annotations, embedded fonts.

Removing this data can reduce file size by 5-25% without losing visual quality.

To clear metadata:

  • 📸 Photo EXIF Editor —removes geotags, shooting date, and other data from images.
  • 📄 Metadata Remover —clears EXIF, XMP, and IPTC from JPEG/PNG.
  • 📑 PDF Metadata Editor —removes authorship, keywords and bookmarks from PDF.

Example: a photo from a camera Samsung Galaxy S23 weighs 8 MB. After removing EXIF ​​via Photo EXIF Editor its size will be reduced to 7.2 MB (~10% savings). For Word documents, the effect is even more noticeable: a file with a history of edits can “lose weight” by 20–30% after cleaning.

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Removing metadata is especially useful before publishing files on the Internet or sending by mail - it not only reduces the size, but also protects your privacy (for example, hides the geolocation of photos).

7. Automation: how to compress files without manual control

If you regularly have to reduce the size of documents (for example, for work or school), set up automatic compression. This will save time and ensure that you remember to optimize files before sending.

Automation methods:

  • 🤖 Automate (scripting application): You can set up a rule "When adding a file to a folder Download compress it to 1 MB and move it to Compressed".
  • ☁️ Google Drive: in the synchronization settings, select "High quality" instead of "Original" - all downloaded images will be automatically compressed.
  • 📂 FolderSync + Photo Resizer: link the folder on your phone to the cloud and configure boot compression.

Example script in Automate:

  1. Block File monitor — monitors folder Downloads.
  2. Block Image resize —reduces resolution to 1200px i quality up to 80%.
  3. Block Move file - moves the result to Compressed/.

This script will work in the background, saving you time.

⚠️ Attention: Automatic compression may conflict with some instant messengers (for example, Telegram or WhatsApp), which themselves optimize media files. Before setting up, check whether the quality of double compression will degrade.

Frequently asked questions

Is it possible to reduce the size of a PDF without losing quality?

Yes, if the PDF contains text without images. Use Adobe Acrobat with the "Compress PDF" option (select "High Quality"). For files with pictures, quality losses are inevitable, but they can be minimized by setting the DPI no lower. 150.

How to compress video on Android?

For video, use Video Compress or InShot. Optimal settings:

  • Resolution: 1280×720 (HD) instead of 1920×1080 (Full HD).
  • Bitrate: 2–4 Mbps for social networks, 8–10 Mbps for archive.
  • Format: .mp4 with codec H.264.

Why did the PDF become unreadable after compression?

This happens if the source file contained low-resolution images (for example, 72 DPI), and you applied aggressive compression. Try:

  1. Open PDF in Adobe Acrobat and export to .docx, and then back to .pdf.
  2. Use Online2PDF with the "Clean PDF" option (removes artifacts).

Which application is best for compressing document scans?

For scans we recommend:

  • CamScanner —automatically optimizes contrast and trims edges.
  • Microsoft Lens —keeps text readable even with high compression.
  • Clear Scanner —allows you to adjust DPI and output format (.pdf or .jpg).

Optimal settings: 200 DPI, black and white mode (if the document has no color elements).

Is it possible to restore the original quality after compression?

No, compression (especially with losses, as in .jpg) deletes data permanently. Always save original files in a separate folder or cloud. The exception is archives (.zip, .rar), which are compressed without loss.