A recipient requests 16-bit PNG. Your converted file is still PNG and has the same dimensions, but neither fact establishes its channel bit depth. Keep the source and inspect the delivered file when 16-bit output is required.
PNG has multiple bit depths
The PNG specification allows 8-bit or 16-bit samples for RGB and RGBA images. The extension alone therefore does not establish the precision of each channel.
Here, 8-bit and 16-bit mean per channel, not a total across all channels and not pixel dimensions. Check the meaning of a reported value before comparing differently named color-depth properties.
What the current converter does
Convert image draws the decoded picture through Canvas 2D before writing PNG, without selecting a high-precision color mode. MDN documents 8-bit channels as the default, and the interface has no 16-bit PNG export control.
In a Chrome test through the website's conversion screen, a 16-bit RGB PNG sample produced a PNG whose header reported 8-bit depth. Do not replace a 16-bit master with this conversion when that depth is mandatory, even if the preview looks similar.
Inspect the required properties
| Requirement | Suggested check |
|---|---|
| PNG format | Actual downloaded file type |
| Width and height | Pixel dimensions, separately from depth |
| 16 bits per channel | Properties reported by a suitable image application |
| A specific color profile | The recipient's color-management workflow |
Increasing dimensions does not restore 16-bit source precision. File size in kilobytes alone is not proof of bit depth either.
Keep purpose-specific copies
- Separate originals from posting or delivery copies.
- Ask whether the recipient requires 16-bit channels or simply PNG.
- For mandatory depth preservation, use an application that exposes and verifies it.
- Reopen the exported file and inspect its properties and important areas.
- Retain the source for further editing or export.
A later 16-bit export cannot reliably reconstruct original values lost in an 8-bit copy. For profiles, see preparing image colors for print. For dimensions, see photo resolution before printing.
