
Website, pricing, platforms and company facts side by side.
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| Website | joinsifta.com | opalstack.com |
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| Company | Startup from the United States · 1 - 9 employees · 2026 | — |
| Listed in |
In their own words, as submitted to SaaSHub.


Sifta is an AI agent that automates your inbox so you never have to open it again. Most people spend hours every week managing email scanning through spam, searching for what matters, worrying about what they missed. Sifta handles all of that for you. It connects to your Gmail or Outlook, stops...
No description of Opalstack yet.
What each product offers, as listed by its team.


Possible disadvantages
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An editorial look at what each product does well and who it suits.


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Overall verdict
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How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing Sifta and Opalstack.
Sifta's answer
We work with hundreds of professionals in the F1000
Sifta's answer
Every other email tool still requires you to open something. A new inbox, a new app, a new dashboard. Sifta is the only email product that removes your inbox from your daily routine entirely. It automates the whole thing in the background and gives you full control through iMessage. You never have to open Gmail again.
Sifta's answer
Superhuman makes your inbox prettier. SaneBox sorts email into folders. Fyxer summarizes what's in your inbox. All of them still require you to open something and do something. Sifta doesn't. You connect your Gmail or Outlook, and Sifta runs your inbox from that point forward. Spam stops. Important emails get texted to you. You reply to take action in plain English. No new behavior. No new interface. No new habit to build.
If you want a better inbox, use something else. If you want to stop living inside your inbox entirely, Sifta is the only product that actually does that.
Sifta's answer
Founders, executives, lawyers, or any professionals who get 50 or more emails a day and can't afford to miss what matters. People whose time is worth more than their inbox management. They've tried other tools and still find themselves stuck inside their email.
Sifta's answer
Sifta was built around one idea: email should be completely automated. You shouldn't have to open it, sort it, or manage it. It should just run. And when something actually needs you, it should come find you not the other way around. That's what Sifta does.
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