RunConvert

PNG to ICNS Converter

Convert PNG to ICNS online for free. Fast, secure, and high-quality conversion with no sign-up or software required.

Free to useNo file stored beyond 1 hourEncrypted over TLS 1.2/1.3No watermarks

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How it works

Three steps to your converted file

Everything happens in your browser tab - upload, pick a format, download. The heavy lifting runs on our servers.

01

Upload your file

Drag and drop, click to browse, or paste a URL. Batches take up to 20 files at once - 230+ input formats across video, audio, image, document, and archive types.

02

Choose an output format

Pick from over a hundred output formats. Filter by category or search by name - every option is open to everyone, no account needed.

03

Convert & download

Hit Convert and grab your download link moments later. Originals are erased when the job completes; results are cleared within about an hour.

What is a PNG file?

Portable Network Graphics (PNG) is a raster graphics file format that supports lossless data compression, created as a patent-free replacement for the Graphics Interchange Format (GIF). Standardized as ISO/IEC 15948:2004, PNG utilizes the DEFLATE compression algorithm (a combination of LZ77 and Huffman coding) and supports palette-based images, grayscale, and full-color non-palette-based RGB/RGBA images. A defining feature is its alpha channel support, allowing for variable transparency levels, unlike the binary transparency of GIF. It does not support animation but offers gamma correction and interlacing via the Adam7 algorithm.

How to open a PNG file

PNG files possess near-universal compatibility across all major operating systems (Windows, macOS, Linux, Android, iOS) and web browsers (Chrome, Firefox, Safari) without requiring additional software. Default image viewers such as Microsoft Photos, Apple Preview, and virtually all graphics editing software including GIMP, Adobe Photoshop, and Paint.NET natively handle the format.

PNG Technical Info

Full Name
Portable Network Graphics
Developed By
PNG Development Group
Initial Release
1996
MIME Type
image/png

What is an ICNS file?

The ICNS format is the standard icon resource file type used by the macOS operating system to display scalable application icons in Finder and the Dock. It acts as a container capable of storing multiple image representations at varying resolutions (from 16x16 to 1024x1024 pixels) and bit depths to ensure visual clarity on diverse display densities, including Retina displays. Internally, ICNS files utilize different compression algorithms based on the icon version, ranging from uncompressed raw data and Run-Length Encoding (RLE) to JPEG 2000 and PNG compression for larger assets.

How to open an ICNS file

ICNS files open natively in macOS using the Preview app. On non-Apple operating systems, standard image viewers generally cannot interpret the multi-resource structure of an ICNS container. Windows and Linux users must employ specialized software such as XnView, IcoFX, or GIMP to view or extract individual icon layers. For conversion to web-friendly formats, command-line tools like libicns or ImageMagick are frequently utilized by developers.

ICNS Technical Info

Full Name
Apple Icon Image
Developed By
Apple Inc.
Initial Release
2001
MIME Type
image/x-icns

Why RunConvert

The fastest way to convert any file

Purpose-built for speed, privacy, and breadth of format support.

Convert PNG to ICNS in seconds

Every PNG to ICNS conversion runs on our servers, so your device stays fast and the output quality stays intact.

Fast, cloud-powered

No queue, no waiting. Files are processed on high-performance servers and returned in seconds, even for large files.

Secure & private

Encrypted in transit and never shared with anyone. Uploads are erased the moment your job completes, and results shortly after.

Free - no account needed

Convert without creating an account - no credit card, no trial clock. Sign in only if you want history and higher daily limits.

Developer API

Convert PNG to ICNS via API

Automate PNG to ICNS conversions in three steps: create a job, upload your file, then poll for the result.

# 1. Create job
curl -X POST https://api.runconvert.com/v3/jobs \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "tag": "png-to-icns",
    "tasks": {
      "upload-file": {
        "operation": "import/upload"
      },
      "convert": {
        "operation": "convert",
        "input": "upload-file",
        "output_format": "icns"
      },
      "export-result": {
        "operation": "export/url",
        "input": "convert"
      }
    }
  }'

# 2. Upload your file (use upload_url from the response)
curl -X PUT "$UPLOAD_URL" --upload-file input.png

# 3. Poll for result
curl https://api.runconvert.com/v3/jobs/$JOB_ID?include=tasks \
  -H "Authorization: Bearer YOUR_API_KEY"

Replace YOUR_API_KEY with your RunConvert API key. Get your free API key at runconvert.com/api.