Working with AI agents on web changes? Stop typing long descriptions. MarkUp lets you annotate any webpage directly — draw what you want changed, label it, and send a structured visual brief to Claude, ChatGPT, or Copilot. Free. No accounts.
Hey All 👋
I'm Michael, the maker behind MarkUp.
I built this because I was spending too much time writing prompts to Claude to explain visual changes on websites.
"Make the nav button more prominent, increase the padding above the footer, increase the trust section's contrast" — by the time I'd typed it all out, I could've made the change myself.
MarkUp turns the live webpage into your prompt. Draw on it. Label it. Send it.
Try it out and let me know your feedback, feature requests, etc. I'm here to build with you.
AMA — happy to dig into how it works, what's coming in v1.1, or how I built it.
Ha cool, literally vibe coded this today for the page I was working on! But much simpler of course, it would just pick up the DOM path + a description I write, no screenshots or drawing or anything. I am sure I could also use this on a page I am working on locally currently and hosting on localhost:8000 let's say, right? Because that is probably the main way I would use, I don't see much need to use it on a live page since that is not where I am iterating on it.
Also, how I put it up for myself was that all the annotations would get saved into annotations.md on my disk (browser would ask once for permissions to write to disk), and I would tell Claude Code to run file watcher on that file and automatically respond to anything I add. Then it would checkmark them when they are done, and I could also edit them either via the tool in the browser or directly in the file if I wish.
About MarkUp on Product Hunt
“Edit websites through AI with visual prompts”
MarkUp launched on Product Hunt on May 8th, 2026 and earned 64 upvotes and 4 comments, placing #45 on the daily leaderboard. Working with AI agents on web changes? Stop typing long descriptions. MarkUp lets you annotate any webpage directly — draw what you want changed, label it, and send a structured visual brief to Claude, ChatGPT, or Copilot. Free. No accounts.
MarkUp was featured in Chrome Extensions (52.6k followers), Design Tools (260.1k followers), Productivity (651.8k followers) and Developer Tools (512.5k followers) on Product Hunt. Together, these topics include over 251.4k products, making this a competitive space to launch in.
Who hunted MarkUp?
MarkUp was hunted by Michael Castelo. A “hunter” on Product Hunt is the community member who submits a product to the platform — uploading the images, the link, and tagging the makers behind it. Hunters typically write the first comment explaining why a product is worth attention, and their followers are notified the moment they post. Around 79% of featured launches on Product Hunt are self-hunted by their makers, but a well-known hunter still acts as a signal of quality to the rest of the community. See the full all-time top hunters leaderboard to discover who is shaping the Product Hunt ecosystem.
Want to see how MarkUp stacked up against nearby launches in real time? Check out the live launch dashboard for upvote speed charts, proximity comparisons, and more analytics.
Michael Castelo