PHP imagetypes() Function: Usage and Examples

Returns a bitmask of compiled-in GD format capabilities (PNG, JPEG, GIF, WebP, AVIF and others, depending on build).

What It Does and When to Use It

Test a format bit in the runtime capability mask. GD operates on raster images in PHP; Imagick delegates to ImageMagick; EXIF reads metadata and is not an image decoder.

Requirements, Inputs and Expected Behavior

Image decoding and encoding need the relevant GD, EXIF, or Imagick support; features vary by PHP build and server. The bitmask describes GD support, not formats present in a particular image.

Example 1: Basic Operation

Test a format bit in the runtime capability mask.

<?php
$formats = imagetypes();
 echo ($formats & IMG_PNG) ? 'PNG available' : 'PNG unavailable';

Example 2: Behavior and Validation

List selected formats only when the corresponding bit is present.

<?php
$capabilities = [IMG_GIF => 'GIF', IMG_JPG => 'JPEG', IMG_WEBP => 'WebP'];
 foreach ($capabilities as $bit => $label) {
     echo $label, ': ', (imagetypes() & $bit ? 'yes' : 'no'), "
";
 }

Practical Example: Application Use

Perform the capability check before using a format encoder.

<?php
if (!(imagetypes() & IMG_WEBP)) {
     throw new RuntimeException('WebP output is not supported by GD');
 }
 $image = imagecreatetruecolor(20, 20);
 try { if (!imagewebp($image, __DIR__ . '/preview.webp', 82)) throw new RuntimeException('Write failed'); }
 finally { imagedestroy($image); }

Important Behavior and Edge Cases

The second example highlights: List selected formats only when the corresponding bit is present. The practical example adds: Perform the capability check before using a format encoder.

Comparison with Related Approaches

Common Beginner Mistakes

Key Takeaways

• Returns a bitmask of compiled-in GD format capabilities (PNG, JPEG, GIF, WebP, AVIF and others, depending on build).
• Perform the capability check before using a format encoder.
• Check image dimensions, true decoder availability, and actual output format rather than trusting a filename suffix.