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ERF to ICO Converter

Convert ERF to ICO 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 an ERF file?

The ERF (Epson Raw Format) is a proprietary raw image format generated by Seiko Epson digital cameras, specifically the R-D1 series. Structured as a TIFF-compliant file, it stores unprocessed sensor data directly from the CCD or CMOS image sensor, preserving high dynamic range and color fidelity prior to demosaicing. The format typically utilizes lossless compression or uncompressed storage to maintain data integrity for post-production, requiring specific Bayer interpolation algorithms to render viewable images.

How to open an ERF file

ERF files are not natively viewable in standard Windows or macOS image viewers without codec extensions. Professional post-processing software such as Adobe Photoshop (via Camera Raw), Adobe Lightroom, and Capture One provide full support for decoding and editing the raw data. For free alternatives, users can utilize RawTherapee or Darktable, which contain the necessary libraries to interpret the specific sensor data from Epson hardware.

ERF Technical Info

Full Name
Epson Raw File
Developed By
Seiko Epson Corporation
Initial Release
2004
MIME Type
image/x-epson-erf

What is an ICO file?

The ICO format is an image container specifically designed for Microsoft Windows to store icons for executable files, folders, and applications. Introduced with Windows 1.0, it can encapsulate multiple raster images of varying dimensions and color depths (specifically BMP or PNG frames) within a single file to support dynamic scaling across different display resolutions. The structure comprises an ICONDIR header referencing one or more ICONDIRENTRY directory entries, allowing the operating system to select the appropriate 16x16, 32x32, or 48x48 pixel resource based on the current UI scaling settings.

How to open an ICO file

ICO files are natively supported by the Microsoft Windows operating system, which automatically renders them in the File Explorer and taskbar. On macOS, Apple Preview handles the format natively. For editing or detailed inspection of the contained bitmap layers, raster graphics editors such as GIMP, Adobe Photoshop (via plugin), or Paint.NET are required. Web browsers also natively render ICO files when they are designated as favicons.

ICO Technical Info

Full Name
Microsoft Icon File
Developed By
Microsoft
Initial Release
1985
MIME Type
image/vnd.microsoft.icon

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Why RunConvert

The fastest way to convert any file

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

Convert ERF to ICO in seconds

Every ERF to ICO 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 ERF to ICO via API

Automate ERF to ICO 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": "erf-to-ico",
    "tasks": {
      "upload-file": {
        "operation": "import/upload"
      },
      "convert": {
        "operation": "convert",
        "input": "upload-file",
        "output_format": "ico"
      },
      "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.erf

# 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.