26 feb 2025
Most email providers limit attachment size to up to 25 MB, which makes sharing large files via email a tricky issue. Yes, cloud storage works, but it also has its own limitations. That’s why sending PDFs, videos, and high-resolution images can eventually become a headache. Luckily, there are other ways to reduce file sizes without sacrificing quality. In this text, we’ll walk you through the best compression methods for different file types.
Email clients allow you to attach files with limited weight. For instance, in Gmail, you can send files of up to 25 MB. If it’s bigger, the platform will automatically upload it to Google Drive and generate a link for your recipient. However, there are two things that make the process inconvenient. First, you’ll have to switch between Gmail and Drive back and forth. Second, the free version of Google Drive has a storage limit of 15 GB. Gmail is just an example. If you take Outlook, you’ll face the same general issue.
So, if you frequently handle large files, you might quickly run low on storage space. In that case, you’ll need to create another account or purchase a subscription (which still has limits). This is where file compression comes in. It minimizes file size and saves you storage space.
PDF is one of the most popular file formats in the world. The PDF Association reported in 2016 that Outlook.com users opened 2 billion PDFs annually, and every day, 73 million new PDF files were saved on Google Drive and sent via Gmail.
Let’s start with smartphones, as file compression is often more challenging on mobile devices. The way to reduce file size depends on the operating system.
If it’s an iPhone, it already has a built-in feature for PDF compression. Find the desired file in the Files app, tap and hold it, choose Quick Actions, and select Optimize File Size.
Another practical solution is to use a tool created specifically for that kind of task. One of the options available is iScanner. This mobile app can reduce the size of your file by up to 80% without losing quality. What is also important is that, unlike basic compression tools, iScanner also allows you to send the compressed file via email directly from the app. There’s no need to switch between an email client and a compressor.
Here’s how to compress your PDF and send it via email with iScanner in six steps:
1. Download and open the iScanner app.
2. Add your file to the app. To do that, tap the Plus button and select the location of the document.
3. Tap the Share button.
4. Activate the Compress button.
5. Choose PDF as the file format.
6. Tap Email in the menu.
That’s it! You can share your file via email now.
Moreover, if you need to make any adjustments to your file, iScanner can fix it as well. You can edit documents in the app, add images and watermarks, create annotations, put an e-signature, convert files into different formats, and even translate them into one of 108 languages.
Android devices don’t come with integrated compression tools, so you’ll need to look for an alternative solution to send large files via email. The Files by Google app is one option. It won’t reduce the actual file size but will compress your documents into a ZIP format. To do this, launch the Files app, tap on More beside the file, choose Compress, and then give your ZIP file a name.
A simpler solution is to try an online tool or a mobile app. iScanner is one of the options. It’ll quickly compress your PDF while maintaining quality. Moreover, it allows you to send the file via email straight from the app.
The flow is the same as on iOS as we’ve described a bit earlier in the text.
On Mac, you can reduce file size without using any third-party applications. Open the file and click the File menu. Choose Export, then find the Quartz Filter dropdown menu and select Reduce File Size. If needed, rename the file in the Export As field and select its destination. Сlick Save, and the compressed PDF will be stored on your computer.
If you’re a Windows device user, Microsoft Word can be of help. Open your file in the program and go to File—Export. Select Create PDF/XPS Document and click the correspondent icon. Choose PDF in the Save as type field. Below that, under Optimize for, select Minimize size (publishing online). Once everything is set, click Publish to save the compressed PDF.
However, there’s one huge disadvantage. Opening a PDF in Microsoft Word may not keep its original formatting. In this case, you can always use an online tool as a way out. If you’re already using the iScanner app on your mobile device, you can also try its web tool for PDF compression.
For sure, a PDF isn’t the only file type you may need to send. Videos, audio files, and images are also shared via email on a daily basis.
Here’s how to compress different file types efficiently:
Large image files can quickly fill up your email storage.
On Windows, right-click the image, select Edit (opens in Paint), click Resize, and adjust the dimensions. Then save the file in a compressed format like JPG.
On Mac, open the image in Preview, go to File, click Export, and adjust the quality slider to reduce file size. This option works well for JPEG, HEIC, and TIFF. However, if you want to significantly reduce the size of a PNG file, you’ll have to look for another solution. For instance, you can convert it to PDF or JPEG and compress the file afterwards.
On iPhone/Android, use the built-in photo editing tool to resize or crop the image before sending.
And here are a couple of online tools that work both on computers and smartphones:
On iPhone, go to Settings, find Camera, choose Formats, and select High Efficiency to save videos in HEVC format. This format will take up less space.
On Android, use the built-in Gallery or Google Photos app to create a smaller version of the video.
Third-party tools like HandBrake, as well as online platforms such as Veed.io, Clideo, FreeConvert, and FlexClip, can also help you reduce video file sizes.
The most convenient option is to use a free converter. VLC, VSDC Free Audio Converter, All2MP3, and Audacity are among them.
