Lottie animations are one of the easiest ways to add motion to websites and applications without relying on large video or GIF files. But there is one common problem: Lottie JSON files can become surprisingly large.
A complex animation exported directly from After Effects may contain thousands of keyframes, unnecessary shape data, hidden layers, excessive decimal precision and other information that increases the file size.
A large Lottie file can mean slower loading, higher bandwidth usage and worse performance on mobile devices.
The good news is that you can often reduce the size significantly without noticeably changing the animation.
Why are Lottie files large?
Several things can increase the size of a Lottie JSON file:
- Too many keyframes
- Complex vector paths
- Unused layers
- Hidden layers
- Embedded raster images
- Excessive decimal precision
- Duplicate assets
- Unnecessary expressions
- Long animation timelines
- Unoptimized After Effects compositions
The problem is usually not the Lottie format itself. The problem is how the animation was created and exported.
1. Remove unnecessary layers
Before exporting your animation, remove layers that aren’t actually required.
Check for:
- Hidden layers
- Disabled layers
- Duplicate layers
- Unused pre-compositions
- Background elements that don’t need to animate
Every unnecessary element can add additional data to the exported JSON.
2. Reduce unnecessary keyframes
One of the biggest causes of oversized Lottie animations is excessive keyframing.
You don’t need a keyframe on every frame to create smooth movement.
Instead, use properly spaced keyframes and easing.
For example, instead of animating an object with dozens of unnecessary position keyframes, you may only need:
Start position → End position → Ease
This can dramatically reduce the amount of animation data.
3. Simplify vector paths
Complex vector illustrations can contain hundreds or thousands of anchor points.
The more points a path contains, the more information Lottie needs to store.
Simplify your paths wherever possible while preserving the visual appearance.
This is particularly important for:
- Illustrations
- Characters
- Logos
- Decorative backgrounds
- Complex icons
4. Avoid unnecessary raster images
Whenever possible, use vector shapes instead of embedded PNG or JPG images.
Raster assets can significantly increase the size of an animation and can also introduce additional loading requirements.
5. Reduce decimal precision
Exported animation data can contain unnecessarily precise numerical values.
For example:
120.837492
may not provide any meaningful visual advantage over:
120.84
Reducing numerical precision can remove unnecessary data from your JSON.
6. Minify your JSON
Lottie JSON is human-readable, which means it can contain whitespace, indentation and formatting that isn’t required for playback.
Minifying the JSON removes this unnecessary formatting.
7. Use a Lottie compressor
If you already have the JSON file and don’t want to manually optimize it, an online compressor can automate much of this process.
Try the free Lottie Wizard Lottie Compressor →
Upload your JSON, compress it, compare the file sizes and download the optimized version.
How much can you reduce a Lottie file?
The result depends heavily on the original animation.
A simple icon may only need a small reduction, while a complex animation containing many shapes and keyframes can potentially be reduced much more.
The important goal isn’t simply achieving the smallest possible file.
The goal is:
Smaller file + identical visual result + reliable playback.
Lottie compression checklist
Before deploying an animation, check:
- Remove unused layers
- Remove unnecessary keyframes
- Simplify complex paths
- Avoid unnecessary raster images
- Remove hidden content
- Minify JSON
- Compress the final file
- Test playback after compression
- Test on mobile devices
- Check the final loading performance
Final thoughts
Optimizing Lottie animations should be part of your production workflow rather than something you do only when a file becomes too large.
Start by optimizing the animation itself, then compress the exported JSON.
If you need a quick way to reduce your file size, try the free Lottie Compressor from Lottie Wizard.