What is async feedback?

Async (asynchronous) feedback is feedback that doesn’t require the reviewer and the developer to be online at the same time. The reviewer leaves their comments whenever it’s convenient, and the developer reads and responds later.

This is in contrast to synchronous feedback, which happens in real-time — like a screen-sharing call where someone points at things and says “change this.”

Why async feedback works for website reviews

Website feedback rarely needs to happen in real-time. A founder reviewing their site at 10pm can leave pinned comments that their developer picks up the next morning. This is especially valuable for teams working across time zones or with freelance developers.

Async feedback tools like Simpl_Markup make this workflow work by:

Opening an interactive preview of the page that captures the current state of the site
Letting the reviewer click directly on the live page to leave comments at any time
Posting comments to Slack so the developer sees them when they’re next online
Tracking which comments are resolved so nothing falls through the cracks

Async vs. sync feedback

	Async feedback	Sync feedback
When	Anytime	Both parties must be online
Tools	Screenshot annotation, Slack, email	Screen sharing, video calls
Documentation	Comments are saved and trackable	Usually lost after the call
Best for	Specific, actionable changes	High-level direction, complex discussions
Time cost	Low (leave comments in 5 minutes)	High (schedule a meeting, share screen)

Best practices for async feedback

Be specific — point at exactly what needs to change, don’t describe it vaguely
One comment per issue — keep each annotation focused on a single change
Include the “why” — not just “change this” but “change this because users might miss it”
Check all devices — review desktop, tablet, and mobile before sending feedback