Capabilities and fallbacks

Call getImageCompressionCapabilities() at runtime. Availability can differ by Android API/device codecs and iOS ImageIO destinations.

Capability	Android	iOS
JPEG/PNG input	Yes	Yes
WebP input	Yes	Static ImageIO decode
GIF input	Static first frame	Static first frame
HEIC/HEIF input	SDK/device gated	Static ImageIO decode
AVIF input	Android 14+ platform decoder	Runtime ImageIO source gated
JPEG/PNG output	Yes	Yes
WebP output	Yes	Runtime ImageIO destination gated
HEIC/HEIF/AVIF output	Not implemented	Not implemented
Target size	JPEG, WebP	JPEG, runtime-available WebP
Animation preservation	Not implemented	Not implemented
Decode-time downsampling	Yes	Yes
Maximum concurrent operations	2	2
Cancellation	Yes	Yes

Both platforms currently report:

{
  maxConcurrentOperations: 2,
  supportsDecodeDownsampling: true,
  supportsCancellation: true,
  resourceLimits: {
    maxSourceDimension: 32_768,
    maxSourcePixels: 100_000_000,
    maxWorkingPixels: 25_000_000,
  },
}

These limits are applied before full decode. Large sources can still be processed when resize bounds permit decode-time downsampling below the working pixel limit.

Fallback pattern

const capabilities = await getImageCompressionCapabilities();

function canOutput(format: 'jpeg' | 'png' | 'webp') {
  return capabilities.formats.some(
    item => item.format === format && item.output
  );
}

const format = canOutput('webp') ? 'webp' : 'jpeg';

Do not infer output support from the input extension. Do not assume another device with the same platform has an identical codec set.

Metadata fallback

preserve is intentionally narrow: JPEG source to JPEG output. Prefer safe for a privacy-filtered/default result and strip when the application does not need metadata. See metadata details.