Free Lottie Stroke Width Editor
Scale or set the line weight of every stroke in a Lottie animation at once — with live preview.
1. Upload your Lottie JSON file
Drag & drop your file here or click to browse
Only .json files (max. 10MB)
Live Preview
Upload a Lottie JSON file to see the preview
Strokes
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Frames
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The Free Lottie Stroke Width Editor Online
Need to make the lines in a Lottie animation thicker or thinner? Our free stroke width editor scales or sets the line weight of every stroke at once — no After Effects required.
Scale keeps the relative differences between lines and preserves any width animation; Set forces every stroke to a single value. Only stroke widths change — fills, colors and timing stay intact. Everything runs locally in your browser.
How to Change Stroke Width in a Lottie
Editing stroke widths by hand means touching every stroke node. This tool adjusts them all in one move:
Upload your Lottie JSON file
Drag and drop or click to browse. The number of strokes is detected automatically.
Choose Scale or Set
Scale multiplies every stroke width by your percentage. Set forces all strokes to a fixed pixel width.
Adjust the value
Drag the slider or type a value. The preview updates instantly.
Download
Save the edited Lottie JSON with the new line weights baked in.
No After Effects, no account, no server uploads — adjust line weight in seconds.
Key Features
Bulk Stroke Control
Adjust every stroke in the animation at once instead of editing them one by one.
Scale vs Set
Scale keeps relative differences between lines; Set makes every stroke a uniform width.
Keeps Animations
Scale mode preserves animated stroke-width keyframes, so any width animation still plays.
Live Preview
See the new line weight the instant you change a setting — no render step.
Popular Use Cases
Match a Design System
Bring an animation’s line weights in line with your UI’s standard stroke thickness.
Bolder Icons
Thicken thin line icons so they read clearly at small sizes.
Thinner, Lighter Look
Reduce heavy strokes for a more delicate, minimal feel.
Consistent Icon Set
Set all strokes to the same width across a batch of icons for a uniform set.
High-DPI Tuning
Adjust stroke weight so lines look right on retina and 4K displays.
Quick A/B Weights
Try a few stroke weights to see which reads best before shipping.
Pro Tips
Scale preserves animation
If a stroke width animates, use Scale so the animation keeps working at the new weight.
Set for a uniform look
Use Set when you want every line at exactly the same thickness regardless of its original width.
Small changes go a long way
A 120–150% scale is often enough to make thin icons noticeably bolder.
Preview at target size
Check the animation at the size you’ll use it — stroke weight reads differently small vs large.
Privacy and Security
We take your privacy seriously. Unlike most online converters that upload your files to remote servers, our tool processes everything locally.
No uploads – Your files are processed entirely in your browser. They never touch our servers.
No tracking – We don't log which files you convert or what settings you use.
No accounts – Use the tool immediately. No registration, no personal data required.
Inspect it yourself – Open DevTools and watch the network tab. You'll see zero file uploads.
Frequently Asked Questions
Everything you need to know about Lottie animations and our tools.
How do I change stroke width in a Lottie?
Upload your Lottie JSON file, then use Scale to multiply all stroke widths by a percentage, or Set to force every stroke to a fixed pixel width. The preview updates instantly.
What is the difference between Scale and Set?
Scale multiplies each stroke’s existing width by your percentage, keeping the relative differences between lines. Set forces every stroke to exactly the value you choose.
Does it keep animated stroke widths?
Yes. In Scale mode, animated stroke-width keyframes are scaled so any width animation still plays. Set mode replaces them with a single fixed value.
Can I make the lines thicker?
Yes — set Scale above 100% (up to 500%) to thicken, or below 100% to thin the lines.
Does it change colors or fills?
No. Only stroke widths change. Fills, colors, shapes and timing are untouched.
Does it work on gradient strokes?
Yes. Both solid strokes and gradient strokes are adjusted.
Are my files uploaded to a server?
No. The entire process happens locally in your browser. Your file never leaves your device.
Is it free?
Completely free, with no registration, watermarks, or usage limits.