First, the disclosure: I make Orbit. You should read everything below knowing that. Second, the thing comparison posts almost never say: Mimestream is a genuinely excellent app. It is beautifully built, it is fast, and for a lot of Mac users it is the right choice. This post exists because the two apps get compared constantly, and they should not be, because they answer different questions. Once you see which question is yours, the choice mostly makes itself.
The one-sentence version of each
Mimestream takes your Gmail data out of the browser and rebuilds it as a real native Mac email client, using the Gmail API. It looks and behaves like a Mac app, because it is one, all the way down.
Orbit goes the opposite way. It keeps Gmail exactly as Google ships it, the real web app, and fixes the part that breaks when you have several accounts: it gives every account its own permanently isolated session inside one native Mac window, with ⌘1–9 to jump between them.
Rebuild the interface, or multiply the real one. That is the whole fork in the road.
What rebuilding gets you (where Mimestream wins)
Because Mimestream renders everything itself, it can do things a web app inside a window never can:
- A true unified inbox. All accounts merged into one list, which Gmail's own interface simply does not offer. If this is the feature you want, stop reading, Mimestream is your answer. Orbit deliberately does not merge inboxes.
- A native Mac feel everywhere. Mac keyboard conventions, system share sheets, real windows and panes. It behaves like Apple Mail with Gmail's brain.
- Speed on the client side. The API approach means the interface itself is lightweight native code, and it shows.
- Wider Mac support. Mimestream runs on macOS 12 and up, Intel included. Orbit requires macOS 14 on Apple silicon.
What rebuilding costs you (where Orbit wins)
A rebuild, by definition, is not the original. Three consequences follow from that, and they are the reasons Orbit exists.
- It is a new app to learn, chasing a moving target. Your web-Gmail muscle memory, settings, and the long tail of Gmail features do not all carry over. Google ships changes to Gmail every week, and an API client is always reimplementing yesterday's Gmail. Orbit shows the real thing, so when Google ships something new, including Gemini in Gmail, you have it the same day, in every account.
- It is email only. Mimestream does mail brilliantly, and only mail. Your day probably also includes Calendar, Drive, and Meet, per account. In Orbit each account carries its full set of Google surfaces, switched together.
- It rents, Orbit owns. Mimestream is $49.99 a year, subscription only, and its own pricing page says the app deactivates if you stop renewing. Orbit is a one-time purchase: $89, paid once, with a 14-day trial and no card up front. By year two Orbit is cheaper either way, and there is no meter running underneath your email.
There is also the isolation point, which matters more the more accounts you have. Orbit gives every account its own cookie store, a genuinely separate session, so accounts cannot interfere with each other and a reply can never quietly go out from the wrong address. And instead of merging inboxes, Orbit's search fans out across every account at once, so “where did that invoice go” is one search, not five.
Mimestream vs Orbit at a glance
- Approach — Mimestream: Gmail rebuilt natively via the API. Orbit: the real Gmail web app, one isolated session per account.
- Unified inbox — Mimestream: yes, its signature feature. Orbit: no, by design; cross-account search instead.
- Beyond email — Mimestream: mail only. Orbit: Gmail, Calendar, Drive, Meet, and Gemini per account.
- Pricing — Mimestream: $49.99/year, deactivates if lapsed. Orbit: one-time $89.
- Fidelity — Mimestream: a very good reimplementation. Orbit: pixel-for-pixel Gmail, because it is Gmail.
- Requirements — Mimestream: macOS 12+, Intel or Apple silicon. Orbit: macOS 14+, Apple silicon.
How to choose in thirty seconds
Pick Mimestream if what you want is a better email client: one merged inbox, Mac-native everything, and you are happy to learn a new app and pay yearly for it. It is the best app in that category, full stop.
Pick Orbit if what you want is Gmail itself, multiplied: several accounts, each with the real Gmail, Calendar, Drive, and Meet you already know, sealed off from each other in one window, paid for once. One early buyer, an Arc user who had tried the whole category, put it like this: “I've tried a ton that didn't work the way I wanted. Orbit feels like it was built just for me.”
A last honest note. If you have one Gmail account, you probably need neither app; the browser is fine. Both of these tools earn their keep when the account count climbs. That is the moment Mimestream answers with a merged inbox, Orbit answers with sealed rooms, and you get to decide which mental model fits your head. Orbit's trial is 14 days, no card, and Mimestream offers the same, so trying both costs you nothing but an afternoon.