PNG Outline Generator

Upload a transparent PNG, create a sticker-style outline around the subject, adjust thickness, color, and softness, then export a transparent PNG.

Last updated: 2026/05/02

PNG Outline Generator

Detect the subject in a transparent PNG and add a sticker-style outline. Adjust color, thickness, softness, and transparent padding, then save the result as a transparent PNG.

Browser-only processing Transparent PNG export
Upload PNG
Up to 12 MB
Click or drag a transparent PNG here
PNG recommended · WebP supported · Images are never sent to the server.
The more transparent the background is, the more accurately the subject outline is detected. Photos with a solid background may produce a mostly rectangular border.
Live preview

The checkerboard is only for checking transparency and is not included in the saved file.

Upload a PNG to create an outline around the subject based on transparent pixels. The result will appear in this preview area.

Outline settings
Based on alpha area
24px
2px
12px
12
100%
Processing summary
Check size and transparency before downloading.
Output size
Waiting for upload
Subject area
Outline settings
24px · #FFFFFF
Transparent background
PNG preserved
Original format
Original resolution
Detected subject
Output resolution
Transparent pixel ratio
Export formatPNG · transparent background
Privacy note: Uploaded files are read and processed only in your browser. Refreshing the page or closing the tab clears the work.

What is the PNG Outline Generator?

The PNG Outline Generator is an image tool that adds an outline around a subject by reading the alpha area of a transparent-background image. Instead of adding a rectangular frame like a standard image border, it follows the real shape of cutout PNG assets such as characters, products, logos, and icons.

  • Create a white sticker-style outline
  • Make product cutouts or character PNGs stand out in thumbnails
  • Export a downloadable PNG while keeping the background transparent

When should you use it?

Transparent PNG edges can disappear when placed on different backgrounds. Adding a subject outline makes the shape clearer on both light and dark backgrounds, so small images such as social stickers, shop thumbnails, and presentation icons remain readable.

  • Prepare character PNGs for merch or sticker mockups
  • Emphasize product cutout thumbnails
  • Improve contrast for icons, logos, and emoji-style graphics

Key features

The tool analyzes transparency in the uploaded image, then expands an outline around the subject. You can control thickness, color, opacity, edge softness, and transparent padding, and auto-trim large empty areas around the original image.

  • Detect the subject from the alpha area of a transparent PNG
  • Quick styles for white stickers, black outlines, gold lines, and soft pink outlines
  • Adjust outline thickness, color, opacity, and softness
  • Auto-trim transparent padding and review the output size
  • Compare with the original and download a transparent PNG

How to use

Start by uploading a PNG with a transparent background. Review the outline around the subject in the preview, choose a quick style or adjust thickness and color manually. If the original has a lot of empty space, keep auto-trim enabled, then save with the PNG download button.

  1. Upload a transparent PNG or WebP image.
  2. Choose a quick style or adjust outline thickness and color.
  3. Check the subject detection threshold and transparent padding trim option.
  4. Compare with the original, then download the transparent PNG.

Tips for natural PNG outlines

A white outline is reliable for most photo and video thumbnails, while a black outline gives strong definition on light backgrounds. Increasing edge softness slightly can make rough cutout pixels look smoother, and raising the detection threshold helps keep semi-transparent shadows or haze out of the outline.

  • Sticker look: white, 20–36 px thickness, 1–4 px softness
  • High contrast: black or dark color, 8–20 px thickness, 0–2 px softness
  • Detailed logo: brand color, 4–12 px thickness, transparent padding up to 8 px

Frequently asked questions

Are images uploaded to the server?

No. Images are processed only inside your browser and are not sent to the server.

Can I use a JPG without a transparent background?

You can use one, but without transparent pixels the tool cannot separate the subject, so the result may look like a border around the whole rectangle. For a true subject outline, use a PNG with the background removed.

Will the result keep a transparent background?

Yes. The checkerboard in the preview is only a screen aid for transparency and is not included in the downloaded PNG.

When should I adjust the detection threshold?

Raise it when semi-transparent shadows or hazy edges are being included in the outline; the tool will detect only more opaque pixels. Lower it if you want to keep thin or semi-transparent details such as hair.

What does auto-trim transparent padding do?

When the original PNG has a large empty area around it, this option crops to the area containing the subject and reduces the output size. Turn it off if you need to keep the original canvas size.

Anything to watch for with large images?

All processing happens in your device browser. Very large high-resolution images can take longer to render, so reducing image dimensions first can make outlining more stable when needed.

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