Intervention/image · error · EncoderException

Failed to encode ico format

Error message

Failed to encode ico format

What it means

The Imagick driver's IcoEncoder clones the native Imagick object, sets format 'ICO' with COMPRESSION_NO (src/Drivers/Imagick/Encoders/IcoEncoder.php:33-37) and serializes with getImagesBlob(). Any ImagickException is rethrown as EncoderException ('Failed to encode ico format') with the original as previous. Besides a missing ICON coder, ICO is spec-limited to 256x256 entries, so encoding oversized images is a classic trigger. Inspect $e->getPrevious()->getMessage() to distinguish the two.

Source

Thrown at src/Drivers/Imagick/Encoders/IcoEncoder.php:44

     */
    public function encode(ImageInterface $image): EncodedImageInterface
    {
        $format = 'ICO';
        $compression = Imagick::COMPRESSION_NO;

        try {
            $imagick = clone $image->core()->native();
            $imagick->setFormat($format);
            $imagick->setImageFormat($format);
            $imagick->setCompression($compression);
            $imagick->setImageCompression($compression);

            $result = new EncodedImage($imagick->getImagesBlob(), 'image/x-icon');
            $imagick->clear();

            return $result;
        } catch (ImagickException $e) {
            throw new EncoderException('Failed to encode ico format', previous: $e);
        }
    }
}

View on GitHub (pinned to 5598b9e397)

Solutions

1. Read $e->getPrevious()->getMessage() for the exact ImageMagick error.
2. Ensure the source fits the ICO spec: resize to 256x256 or smaller (favicon sizes are typically 16/32/48/64) before calling toIco().
3. Confirm the coder exists via Imagick::queryFormats('ICO'); if empty, install a full ImageMagick build and rebuild the imagick extension.
4. Prefer dedicated favicon tooling for multi-size .ico generation and use toPng() for single-size icons.

Example fix

// before
$ico = $manager->read('logo-1024.png')->toIco(); // fails: ICO entries max out at 256x256

// after
$ico = $manager->read('logo-1024.png')
    ->resize(256, 256)
    ->toIco();

$icoSupported = in_array('ICO', Imagick::queryFormats('ICO'), true);
$icoSized = $image->width() <= 256 && $image->height() <= 256;
if (!$icoSupported || !$icoSized) {
    throw new RuntimeException('ICO output requires the ICON coder and dimensions <= 256x256');
}
$encoded = $image->toIco();

try {
    $encoded = $image->toIco();
} catch (EncoderException $e) {
    $reason = $e->getPrevious()?->getMessage() ?? $e->getMessage();
    $encoded = $image->toPng(); // browsers accept PNG favicons, then log $reason
}

When it happens

Trigger: Calling toIco() on the Imagick driver when the ICON coder is absent (custom/minimal ImageMagick builds), or when serializing images whose width or height exceeds the 256-pixel ICO limit, causing getImagesBlob() to fail. Verify with php -r "var_dump((new Imagick())->queryFormats('ICO'));".

Common situations: Generating favicons from full-size source images without downscaling; automated asset pipelines that feed arbitrary uploads to toIco(); stripped Alpine/static ImageMagick builds without the ICON coder.

Related errors

• Failed to encode avif format
• Failed to encode bmp format
• Failed to encode gif format
• Failed to encode heic format
• Failed to encode jp2 format

AI-assisted analysis of Intervention/image@5598b9e397 (2026-08-23). Data as JSON: /api/errors/d2096ddf07eff096. Report an issue: GitHub.