What is usually better for messages: blur or pixelate?
Blur is softer and often better when the screenshot should still look natural. Pixelate makes the redaction more explicit when the message content must read as fully masked.
Can I use boxes for chat screenshots too?
Yes. Black and white boxes remain available if a solid mask fits the design of the screenshot better than blur or pixelation.
Does this happen locally?
Yes. The screenshot is edited and exported in the browser without server-side image processing.
Should I blur or box out chat messages?
Box them. Chat is rendered in a known system font at a known size, which is precisely the condition under which blurred and pixelated text can be reconstructed. An opaque box destroys the pixels.
What else identifies the conversation besides the messages?
The display name, the avatar, the phone number or handle in the header, the group name, timestamps, read receipts, and often a distinctive wallpaper. Redacting the bubbles and leaving the header is a common and complete failure.
Is it better to crop than to mask?
Usually. If you only need to show two messages, crop to those two messages. Everything outside the crop never enters the exported file, which is a stronger guarantee than any mask.
Can I blur only the profile pictures?
Yes, and that is a reasonable use of blur. An avatar has no alphabet behind it, so the text-reconstruction attacks do not apply. Keep boxes for anything with characters in it.
Does anything get uploaded?
No. The screenshot is decoded, redacted and re-encoded in your browser, which is the only sensible way to handle someone else's private messages.