Why are the edges jagged or pixelated?

Why edges look jagged

Jagged edges happen when the AI mask transition is too abrupt — pixels snap between fully opaque and fully transparent instead of graduating smoothly. Several things can cause this:

1. Low-resolution input — the AI has less information to work with, so boundaries are less precise
2. Hard-edged subject — objects with very clear geometric boundaries (a box, a logo) will have naturally harder edges; the AI correctly keeps them sharp
3. Model sensitivity — the Fast (RMBG-1.4) model is more likely to produce slightly harder edges on complex subjects than the Best Quality (RMBG-2.0) model
4. Over-smoothed original — heavily compressed JPEGs lose the fine detail the AI needs to make smooth decisions

Fix 1: Feather

Feather applies a Gaussian blur to the mask edge, creating a smooth gradient from opaque to transparent. This is the fastest fix for systematic jaggedness.

1. Open the editor
2. Go to Edge Refinement
3. Set Feather to 2–5 px for subtle softening, 8–15 px for a pronounced effect
4. Adjust until the edge looks natural

Caution: Too much feathering makes subjects look out-of-focus or glowing. Start low and increase gradually.

Fix 2: Smooth

The Smooth slider applies a morphological smooth to the mask contour. Unlike feathering (which blurs the edge), smoothing simplifies the shape of the boundary — it rounds sharp corners and removes jagged bumps while keeping the edge crisp.

Use Smooth before Feather. They work well together:

1. Smooth: 3–6 to clean up the jagged contour
2. Feather: 1–3 to add a slight softness

Fix 3: Best Quality model

If you're consistently getting jagged results with the Fast model, switch to Best Quality (RMBG-2.0) before processing. This model produces significantly better edges on complex subjects, especially hair, fur, and foliage.

To switch: click the model selector above the upload zone, select Best Quality, then re-process the image.

Fix 4: Brush tool for isolated problem spots

If only one part of the edge is jagged (a specific corner, a patch of fur), use the brush tool to manually refine it. Use low hardness (20–40%) to paint soft transitions.

Fix 5: Process a higher-resolution image

If your original is small (under 500 px wide), the AI has limited pixels to work with. If you can get a higher-resolution version of the image, the result will be noticeably better.

When to leave edges sharp

Some subjects should have sharp edges: logos, icons, printed packaging, objects with clean geometric shapes. For these:

• Turn off Preserve soft edges in Edge Refinement — this thresholds the mask to binary (fully on or fully off)
• Use a high Smooth value to clean up any jaggedness
• Avoid feathering

Related

• Edge refinement
• Using the brush tool
• General troubleshooting