When uploading photos to Facebook, many users notice a reduction in image quality or resolution. There are a few reasons why Facebook compresses and resizes images.
Opening Paragraphs
Facebook’s image compression allows files to upload and download quicker, saves server storage space, and improves performance across platforms. The social network optimizes images to load efficiently on desktop, mobile web, and in the Facebook mobile apps. Compression ensures a consistent experience for users, regardless of their device or network speed.
Facebook’s resize algorithm also creates multiple cropped versions of each photo to display in the News Feed and galleries. As people view Facebook on various screen sizes, having pre-generated crops enhances page speed.
Overall, the image compression and resizing applied by Facebook provides practical improvements to social sharing. But it can come at the cost of reduced quality, depending on the original photo’s size and format.
Image Upload and Compression
When you upload a photo to Facebook, it goes through the following process:
- Facebook checks the image metadata and orientation.
- The system generates cropped versions for different layouts.
- Your original is compressed to save storage space and bandwidth.
- The resized and compressed versions are stored and optimized for display.
The amount of compression depends on the image’s resolution and file size. Facebook compresses JPEGs with a quality setting ranging from 75-80% quality. Compared to the typical 95-100% quality of camera JPEGs, this results in smaller file sizes and reduced image clarity.
The compression applied to PNG files can reduce quality even further. Facebook converts PNGs to JPEGs, usually at lower quality settings around 30-50%. This significantly degrades detail and introduces JPEG compression artifacts.
Maximum Upload Resolution
In addition to compression, Facebook resizes images by limiting the maximum upload resolution. As of 2022, the largest image size allowed is 12MP or 4,032 x 3,024 pixels.
If your image exceeds 12MP, Facebook will scale it down during the upload process. For example, a 18MP camera photo measuring 5,184 x 3,456 pixels would be resized to ~4,000 x 2,600 pixels.
This automatic resizing prevents excessively large files that would strain Facebook’s servers. But it also degrades quality for photographers uploading high-res pictures from newer DSLR and mirrorless cameras.
Cropping and Resizing for Display
After upload, Facebook generates multiple cropped versions of each photo to display across different parts of the platform:
- News feed posts
- Individual photo pages
- Profiles and cover photos
- Shared photo albums
- Facebook Stories
- Ads and boosted posts
Creating these optimized crops in advance speeds up loading as users scroll through the News Feed and photo galleries. The cropped versions are also compressed to around 75-80% JPEG quality.
Some examples of Facebook’s automated cropping:
- Post thumbnails in the News Feed are resized to 526 x 297 pixels.
- Full-width single photo posts are 828 x 315 pixels.
- Shared album views display photos at 960 x 720 pixels.
With each crop, image details get discarded to fit the smaller dimensions. This causes additional softening and quality loss compared to the original upload.
Image Formats and Quality
Because Facebook converts all photos to compressed JPEGs, the format of your original makes a difference in retention of quality.
JPEG is a “lossy” format, meaning information is lost each time the image is edited and saved. So uploading a JPEG to Facebook then downloading it will degrade quality compared to the camera original.
PNG files are lossless, but Facebook converts PNGs to low quality JPEGs during upload. This change in format significantly impacts visual quality.
RAW camera photos contain uncompressed image data that allows higher quality processing. But Facebook does not support RAW formats, and will compress the JPEG preview embedded in RAW files.
For best results, edited JPEGs exported at 95-100% quality retain more detail through Facebook’s process. Avoid re-saving JPEGs at lower quality before uploading.
Image Optimization Techniques
To balance performance and quality, Facebook uses industry standard image optimization and compression algorithms. The main techniques include:
- Chroma Subsampling – Reduces color resolution while maintaining luminance detail.
- Quantization – Approximates color values to reduce file size.
- Downsampling – Scales down image dimensions.
- JPEG Compression – Identifies redundant image data to remove.
These methods aim to reduce file size with minimal perceived loss in image quality. However, high amounts of compression multiplied by uploading and downloading can still visibly degrade photos.
Image Optimization Goals
Facebook’s photo processing serves a few core goals:
- Smaller file sizes to save bandwidth on upload and download.
- Faster loading images across all user devices and networks.
- A consistent Facebook experience on mobile, desktop, apps.
- The ability to store billions of photos at scale.
Some image quality is sacrificed to achieve these performance and consistency targets. But photos can still look great on Facebook, as long as users understand the limits and optimize their originals accordingly.
Maintaining Photo Quality for Social Media
Keeping images crisp on Facebook involves following best practices when editing and exporting photos:
- Avoid extreme cropping or enlarging. Scale images close to intended display size.
- Export and re-save JPEGs at 95-100% quality.
- When possible, upload edited JPEGs instead of PNGs.
- Size images around 12MP and 4000 pixels wide.
- Add little or no JPEG compression during edits.
- Avoid filters, noise reduction, and sharpening that harm detail.
With high-quality originals and reasonable expectations, your photos can continue looking great through Facebook’s process. Focus on elements like composition, color, and subject matter when capturing shots to share socially.
Improving Facebook’s Image Quality
For photographers hoping to maintain maximum image quality, there are some alternate options:
- Google Photos – Offers free unlimited storage for high resolution photos.
- Flickr – Allows original image uploads up to 200MB.
- 500px – Displays photos without reducing resolution.
Many social sites like Twitter and Instagram also compress images. For portfolio-level quality, display your best work on a professional photography website.
Overall, the convenience of Facebook image sharing comes with quality trade-offs. But keeping images crisp involves both understanding the technical processes and starting with great photographs.
Conclusion
Facebook’s compression and resizing trades off some image quality for efficient performance across devices and networks. Photos go through scaling, cropping, JPEG encoding, and color reduction during the process. While this degrades detail, starting with quality originals and following best practices can help photos continue looking great when shared socially.