Free tools
See more at once
Multi-site viewer
Put several websites side by side in one browser tab — free, no sign-up.
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Responsive tester
One page at phone, tablet, laptop and desktop widths, all at once.
See more at once
Multi-stream viewer
Twitch and YouTube side by side, with a link that shares the whole lineup.
Embeds
Embed checker
Check any site’s X-Frame-Options and frame-ancestors, explained in plain words.
Embeds
Iframe generator
Responsive iframe code for any page, with YouTube, Maps and Figma handled for you.
Your browser
Ad blocker test
Test your ad blocker against the networks and trackers that follow you around.
Your browser
What browser am I using?
Your browser, version, engine and OS — detected instantly, ready to copy.
Switching browsers
Arc exporter
Every space, folder and pinned tab as a bookmarks file any browser imports.
Switching browsers
Open multiple URLs
Paste a list or any text with links in it and open them all at once.
Switching browsers
Browser comparison
Twelve browsers, ten features, side by side — Tabula included, flaws and all.
Looking for comparisons and guides instead? The Atlas has honest write-ups of Arc, Zen, Dia and the best browsers for Mac.