Staaarter Tools

Logo Shadow Adder

Uploads a logo PNG and builds a blurred, offset, colored silhouette behind its visible content, then composites the original logo back on top, producing a drop-shadow effect with a canvas expanded to fit the full shadow bleed. A free online tool from Staaarter, right in your browser.

Runs locallyUpdated 2026-07-26
editoreffectimagecanvaspng

Overview

Introduction

This tool adds a soft drop shadow behind a logo, entirely in your browser, giving it a sense of depth against a flat background.

It's a quick way to make a flat logo feel like it's floating above the page rather than sitting flush against it.

What Is Logo Shadow Adder?

A client-side shadow generator that builds a colored, blurred silhouette of the logo's own shape, offsets it, and composites the original logo on top of that shadow.

The canvas automatically expands to fit the shadow's full offset-plus-blur bleed so nothing gets clipped.

How Logo Shadow Adder Works

A silhouette tinted with the shadow color (its alpha scaled by the source pixel's own alpha) is built from the logo, blurred by the chosen radius, and offset by the chosen X and Y amounts.

The original logo is then alpha-composited on top of that shadow using standard source-over blending, so the sharp logo always sits above its own soft shadow.

When To Use Logo Shadow Adder

Use it to give a flat logo a subtle sense of depth for a hero section, presentation slide, or app icon.

It's also useful for making a light-colored logo stand out more against a similarly light background.

Often used alongside Logo Outline Adder, Logo Space Adder and Semi-transparent Logo Creator.

Features

Advantages

  • Runs entirely client-side; your logo file is never uploaded anywhere.
  • The shadow automatically follows the logo's exact silhouette rather than a generic rectangle.
  • Offset, blur radius, and shadow color/opacity are all independently configurable.

Limitations

  • Larger blur radius and offset values expand the canvas further, which can push a large logo past the 4096px maximum output dimension.
  • The shadow effect works best against a plain or transparent background; it can look inconsistent when later placed over a busy photo.

Examples

Add a subtle floating shadow

Input

A logo PNG, offset 4x4, blur 4, black shadow at 60% alpha

Output

The logo with a soft dark shadow trailing slightly down and to the right

Small offset and blur values produce a subtle, realistic-looking depth effect.

Add a bold sticker-style shadow

Input

A logo PNG, offset 8x8, blur 0, solid black shadow

Output

The logo with a hard-edged, offset silhouette behind it, like a sticker drop shadow

Zero blur keeps the shadow's edge crisp instead of soft, for a bolder graphic look.

Best Practices & Notes

Best Practices

  • Keep offset and blur proportional to the logo's own size — a huge shadow on a small logo can look exaggerated.
  • Use a lower shadow alpha (100-160) for a subtle, realistic effect rather than a heavy black block.

Developer Notes

The lib function is a thin re-export of the already-shipped addShadowToPng from the base shadow-adder tool, since a logo is just a PNG once it's uploaded — the compositing and blur math isn't duplicated here.

Logo Shadow Adder Use Cases

  • Adding depth to a logo displayed on a hero banner
  • Making a light logo stand out on a light-colored background
  • Creating a stylized sticker-shadow variant of a brand mark

Common Mistakes

  • Setting blur and offset so high the canvas hits the 4096px cap and the tool rejects the result.
  • Using full-opacity black for the shadow color, which often looks harsher than a semi-transparent shadow.

Tips

  • Combine with the space adder first if you need extra margin for a very large shadow bleed.
  • Try a colored shadow (not just black) that complements your brand palette for a more polished look.

References

Frequently Asked Questions