SigmaOS vs Vivaldi (2026): which should you pick?
As of Nov 12, 2026, Vivaldi grades higher than SigmaOS: 3.8 against 2.4 out of 4.0.
Checked Oct 5, 2026 and Nov 12, 2026 · graded Oct 10, 2026 and Nov 12, 2026 by ToolGPA
Vivaldi grades higher on the free plan, features, ease of use and platforms. They get the same grade on value for money.
Price, platforms and features side by side. The table says where each price was read and when.
SigmaOS
Mac browser with vertical tabs, workspaces and an AI assistant
Which one is for you
Pick SigmaOS if
- Fits if you live on a Mac and want tabs down the side in separate workspaces
- Works for people who want an assistant that answers questions about the page
Look elsewhere if
- Not for you if you use Windows or Linux, as it runs on macOS only
- Pricey if you want unlimited AI, which needs Pro at $20 a month
- Watch out: the help docs list an older Pro price of $10 a month, against $20 on the homepage
- Watch out: iOS and Windows versions are described as coming, and pages on the site carry a 2024 copyright notice
Pick Vivaldi if
- Fits if you keep dozens of tabs open and want them stacked, split and sorted
- Works for people who want mail, calendar and feeds in the same window as their tabs
Look elsewhere if
- Skip it if you want a chatbot or page summaries built in, because Vivaldi leaves AI out on purpose
- Not for you if you want the free VPN on your phone, as it only works in the desktop browser
- Pricey if you want faster VPN speeds, more servers or extra devices, which need a paid Proton VPN plan
- Watch out: new installs come with partner bookmarks and search engines that earn Vivaldi revenue until you replace them
- Not for you if your Mac is older than macOS 13, which the current download needs
How we grade them
| 2.4GPASigmaOSFair | 3.8GPAVivaldiExcellent | |
|---|---|---|
| Value for money | AThe Personal plan is described as free forever, so the browser costs nothing. Unlimited Airis needs Pro at $20 a month, which is where this category's dearest tenth starts. | AFree on every platform with no paid tier at all, and the reason is on Vivaldi's own blog: it earns from search and bookmark partner deals, a cut of Proton VPN upgrades and donations, rather than from you. There's nothing to buy and nothing withheld. |
| Free plan and trial | BA free-forever plan one person could live on, with the AI helper limited rather than missing. | AFree outright, with mail, calendar, feed reader, notes, the ad and tracker blocker, end-to-end encrypted sync, and Proton VPN on the desktop with no ads or data limit. New installs arrive with partner bookmarks you can swap out. |
| Features | CWorkspaces, vertical tabs, search across tabs and an ad blocker. Unlimited AI use is Pro only, and the help docs list an older Pro price of $10 against the homepage's $20. | AIt builds in an email client for several accounts, a calendar, a feed reader and notes, with an ad blocker, two-level Tab Stacks, tiling, Workspaces and Command Chains that fire a string of commands off one keystroke. The deliberate gap is AI: there's none, by choice. |
| Ease of use | CNo store rating on record. Workspaces, profiles and keyboard-first search take some learning. | A4.73 from about 4,400 App Store ratings. You can leave it exactly as it comes, or change shortcuts, themes and layout until it fits. There's a lot in here, so give it an evening. |
| Platforms and integrations | DmacOS only. The FAQ says iOS and Windows support are coming. | BWindows, Mac, Linux, Android and iPhone, with history, passwords, bookmarks, tabs and notes synced end-to-end encrypted. Computers and both phones is a B here, because our top mark also wants a web app and a browser isn't one, and Proton VPN is the only integration listed. |
| Best for | a Mac browser with vertical tabs and an AI helper | tab hoarders who like to customise everything |
The GPA is the average of the five grades: an A is 4 points, an F is none. The full reasons are on each tool's page: SigmaOS and Vivaldi. How we grade
Price against what you get
SigmaOS starts at $20 a month and scores 1.7 out of 4 on features, ease of use and platforms. Vivaldi has no paid plan and scores 3.7.
Vivaldi scores higher and starts $20 a month lower. Of the other browsers on the chart, 22 score higher than SigmaOS for less, and none scores higher than Vivaldi for less.
Features, ease of use and platforms, averaged
What paid plans start at, a month (each step along is roughly double) →
- The best score at each price
- Has a free plan
- No free plan
Where they differ
- Vivaldi is end-to-end encrypted, according to its own site.
- SigmaOS also covers ad and tracker blocking.
- Vivaldi also covers notes, calendar, email client, screenshots and rSS reader.
At a glance
| SigmaOS | Vivaldi | |
|---|---|---|
| Pricing | Free plan | Free |
| Starts at | $20 per month (Pro) | Free |
| Free plan | SigmaOS Personal is described as free forever; unlimited Airis AI usage is a Pro feature. | Vivaldi is free on desktop and mobile with no paid tier. The company funds itself through search engine and bookmark partner deals, a share of Proton VPN upgrades and donations. |
| Free trial | None listed | None listed |
| macOS | ||
| Windows | ||
| Linux | ||
| iOS | ||
| Android | ||
| Made by | SigmaOS, Inc. | Vivaldi Technologies |
| Price read from | sigmaos.com | apps.apple.com |
| Checked | Nov 12, 2026 | Oct 5, 2026 |
Worth knowing
SigmaOS
- It runs only on macOS; the FAQ says iOS and Windows support are coming.
- Unlimited Airis usage needs the paid Pro plan.
- The company's help docs list an older Pro price of $10 per month ($8 billed yearly); the homepage FAQ says $20 a month. Check the price in the app before buying.
- Pages on the site carry a 2024 copyright notice.
Vivaldi
- Proton VPN for Vivaldi works only in the desktop browser, and faster speeds, more servers and extra devices need a paid Proton VPN plan.
- New installs come with partner bookmarks and search engines that earn Vivaldi revenue. They can be replaced.
- Vivaldi deliberately leaves out an AI assistant, so there is no built-in chatbot or page summarizer.
- The current Mac download requires macOS 13 or later.
Key features
SigmaOS
- Workspaces and vertical tabs
- Tabs are kept in separate workspace lists down the side of the window, and a workspace can use separate profiles to sign in to different accounts.
- Tabs as tasks
- Tabs can be marked as done when finished or locked to a workspace to keep them.
- Lazy Search
- Pressing the spacebar searches across open tabs, the web, commands and bookmarks.
- Airis assistant
- The AI companion can answer questions about the page you are on, search the web and read several pages at once, and a Simplify view summarizes a page.
- Ad blocker and Focus Mode
- A built-in ad blocker is included, and Focus Mode hides everything except the current page.
- Chromium extensions
- The FAQ says SigmaOS is a WebKit browser that also supports Chromium extensions.
Vivaldi
- Mail, Calendar and Feed Reader
- A built-in email client handles several accounts, mailing lists and feeds in one inbox, next to a private calendar and a feed reader that does not rank items by algorithm.
- Tab Stacks, tiling and Workspaces
- Tabs group into two-level Tab Stacks, open side by side in a split-screen view, and sort into Workspaces for switching between categories of tabs.
- Ad and tracker blocker
- A blocker for ads and trackers is built into the desktop and mobile browsers, so no extension is needed to remove them.
- End-to-end encrypted Sync
- Browsing history, passwords, bookmarks, tabs and notes sync between desktop and mobile devices, protected by end-to-end encryption.
- Proton VPN for Vivaldi
- An opt-in VPN from Proton is built into the desktop browser. It is free with no ads or data limits after signing in with a Vivaldi account.
- Customization and Command Chains
- Shortcuts, themes and features can be personalized, mouse gestures trigger actions, and Command Chains run a custom sequence of commands from one keystroke or gesture.
Plans
SigmaOS
Personal$0
The browser for macOS, free, without unlimited Airis AI usage.
Pro$20
per month; billing basis not stated on the page
Unlimited Airis usage. The site says Pro starts at this price and gives students and educators 50% off.
Vivaldi
Free$0
The full browser on Windows, macOS, Linux, Android and iOS, including mail, calendar, feed reader, sync and the free tier of Proton VPN on desktop.
Ways to pay less
SigmaOS
- Education
50% off Pro for students and educators
The homepage FAQ says students and educators are eligible for a 50% discount on SigmaOS Pro.
Vivaldi
No public discounts listed.
Common questions
Which is cheaper, SigmaOS or Vivaldi?
As of Nov 12, 2026, Vivaldi is cheaper to start with: it is free, against $20 a month for SigmaOS. SigmaOS starts at $20 per month (Pro), and Vivaldi is free.
Which has a free plan, SigmaOS or Vivaldi?
As of Nov 12, 2026, both SigmaOS and Vivaldi have a free plan.
Which platforms do SigmaOS and Vivaldi run on?
As of Nov 12, 2026, only Vivaldi lists Windows, Linux, iOS and Android apps. Both list a macOS app. A platform missing from a listing is one its maker's pages did not mention.
More comparisons
How this page was made
- The verdict at the top follows a fixed rule. When both tools are in the same category and either is in our top three for it, the verdict follows that ranking: the higher-placed tool is our pick. The top three weigh who each tool suits as well as its grades, so a pick can go against the GPA. Otherwise the page does not pick one and says which grades higher: the higher GPA first; on a tie, the one with a free plan, then the one that starts cheaper in dollars a month, counted the same way for both; if they are still level, what the choice depends on.
- The grades are our own, from each tool’s review or report card. The GPA is their average.
- Prices, plans and platforms come from each tool’s listing. The table above says where each price was read and when.
- The differences and the answers to the questions are worked out from those listings.