MyBroadband tested sending media files as documents on WhatsApp and found it significantly impacted image quality, especially on higher resolution images.
When sending an image or video over WhatsApp, the file is scaled to a lower resolution to save on data, which reduces the quality of the received image.
While this is fine for casual image sharing, problems arise if you want to send a higher resolution image or video to someone for professional use.
Fortunately, WhatsApp lets you send images and videos as documents, bypassing its compression mechanism and ensuring the quality does not suffer.
MyBroadband tested this by sending six images and a video clip using WhatsApp’s media sharing option and then sending the same files as documents.
These files were downloaded on the same device side, and the resolution, file size and quality were compared.
The images were originally either 8160×6120 or 4000×3000, and all ended up as 1600×1200 when shared as pictures in a WhatsApp chat.
They all kept their original resolutions when sent as documents.
The video initially had a resolution of 1920×1080 and a framerate of 30 frames per second.
While the framerate remained the same, the one sent as media ended up with a resolution of only 640×352.
The images we sent the usual way ended up with file sizes less than 10% of the original, while the video shrunk to 14% of its original size.
This makes for a significant data saving, which explains why this is the default method to send images and videos.
|WhatsApp Image Compression|
|Test file||Original Resolution||Original Size||WhatsApp Resolution||WhatsApp Size|
|Image 1||8160×6120||6.74 MB||1600×1200||142 KB|
|Image 2||8160×6120||4.99 MB||1600×1200||126 KB|
|Image 3||8160×6120||8.18 MB||1600×1200||221 KB|
|Image 4||3000×4000||1.48 MB||1200×1600||128 KB|
|Image 5||3000×4000||1.99 MB||1200×1600||84.7 KB|
|Image 6||4000×3000||2.68 MB||1600×1200||202 KB|
|Video 1||1920×1080||7.21 MB||640×352||1.01 MB|
When comparing the resulting image quality of the two methods, we looked at small, detailed parts of each image.
It was immediately apparent that WhatsApp’s image compression is very lossy to achieve the high data savings we measured.
As expected, the quality reduction was more evident in images with a higher starting resolution.
The reduction in the video quality was worse than the image compression, with even the colours looking different from the original.
We also tried going into WhatsApp’s Storage and Data settings and changing the upload quality to the “best” option instead of “auto”, but this made no difference to the results.
While sending images and videos as documents is not recommended for day-to-day sharing due to the data use, it is a handy trick to remember when you need a photo or video in all its original glory.
Zoomed portions from some images and a frame from the video are included below to show the quality differences.