Facebook's image compression is among the most aggressive of any major social platform. Every photo you upload — regardless of how good your original looks — gets re-encoded by Facebook's servers to reduce file size and save bandwidth. Understanding why this happens is the first step to preventing it.
| Cause | What Happens | How to Prevent |
|---|
| Uploading a photo that is too large | Facebook's server resizes it down to fit the display dimensions, applying heavy compression during the resize. A 5MB photo from your camera becomes a 100KB Facebook image with visible artifacts. | Upload at exactly the target dimension (e.g., 820x312px for Cover). When Facebook does not need to resize, it applies less compression. |
| Uploading a JPG with text, logos, or sharp edges | JPG compression creates block artifacts (the 'blocky' effect) around high-contrast edges and text. This is inherent to how JPG works, not a Facebook-specific bug. | Save images with text, logos, or graphics as PNG before uploading. PNG compresses differently and preserves sharp edges much better than JPG at Facebook's target file sizes. |
| Uploading a JPG that has already been compressed | Re-compressing an already-compressed JPG (double compression) multiplies the artifacts. A photo saved at JPG quality 80%, then re-saved at quality 80%, looks far worse than a single save at quality 60%. | Start from your original highest-quality source file. Never re-save a JPG that has already been through Facebook or another compressor as your source. |
| Profile Picture displayed too small | Facebook displays Profile Pictures at 170x170px on desktop but only 32x32px in comments. A photo that looks fine at 170px may appear blurry at 32px if the subject is not centered and clearly legible at small sizes. | Upload at 180x180px or higher. Use a close-up crop centered on the face or logo – detail that is visible at 170px may disappear at 32px. |
The single most effective fix: Resize to the exact target dimensions before uploading (which this tool does automatically), and save as PNG for any image containing text, logos, or sharp graphics. For standard photos without text, high-quality JPG is acceptable.
Resize done — compress before sharing?