OneCal is a reliable and simple solution to Calendar syncing. It handles integration with Microsoft 365 and Apple Calendar pretty well. I like it because it let's me have personal Apple Calendar events block out time on my work calendar. Having my work calendar reflect my actual availability without including personal details is important to me, and OneCal does the trick. The pricing is a little bit high for my use case, but worth it to me. The UI is a little frustrating sometimes, and I would not use their native calendar view as my default calendaring app. It can be a little slow, but this is understandable. I also appreciate the extra features like booking links, which are much more polished than Microsoft Booking. Review collected by and hosted on G2.com.

I don't have any real frustrations with OneCal. The UI could be improved a little, and their native calendar app could be a little more feature rich and responsive, but this is not my use case anyway. Review collected by and hosted on G2.com.

I love the seamless multi-calendar integration feature in OneCal. Having one place to reconcile multiple calendars is incredibly helpful for me. Additionally, the programmatic interaction through the MCP or the API is fantastic as it allows my AI agent to manipulate my calendar behind the scenes effectively, reducing my frustration, stress, and freeing up my time significantly. Review collected by and hosted on G2.com.

I think OneCal could improve by adding location autocomplete for new event creation. It would also be great if it could integrate better with Google Contacts or any contact manager so events can auto-complete with the right details. That'd be really cool. Review collected by and hosted on G2.com.

The support responsiveness. I sent a small feature request through the feedback form (preselecting the meeting duration in a booking link) and had it shipped and live 34 minutes later, with the new URL parameter and a short-domain variant. Review collected by and hosted on G2.com.

Two small usability gaps. To add a colleague to a joint team booking link, they first have to onboard and create a booking link of their own, which confuses new users and adds a step nobody expects. And the limit of two connected calendar accounts is tight for people juggling several. Neither has been a real blocker for us. Review collected by and hosted on G2.com.

I'm a consultant. I have 4 different google calendar accounts w/ different companies. The specific issue I needed to solve was that when I put something on one calendar, I needed it to block all of the other calendars. This seamlessly and effortlessly makes that possible. I've used it for 2-3 years now and it's perfect. Review collected by and hosted on G2.com.

Very occasionally, you have to jump in and give it a nudge by manually re-running the sync. But that's like once every several months, and not a burden for the value I get in all of the other time that it is automated. Review collected by and hosted on G2.com.

The user interface is intuitive and clean, setup is easy and there's little to no maintenance needed. I didn't read a single support article because it all just ... makes sense to set up. It offers a variety of options in configuring the sync so that you share only what you want. The syncs are fast and it stays up-to-date in realtime. I love the booking links and the public calendar and ICS features. I have 9 calendars to manage and it has saved my life. It's made it so easy for colleagues and clients to see my actual availability and schedule with me without needing to share my calendars directly with one another. It's a perfect solution to my problem. Review collected by and hosted on G2.com.

I'd like to see the ability to add more than 8 calendars and I'd love more integration options. For example, I'd like to use my notetaker across all my calendars. I'd really like the ability to mark events on specific calendars as billable and see the totals for the week. Review collected by and hosted on G2.com.

I think it's great that OneCal keeps track of my appointments, especially since I manage multiple companies and accordingly multiple email accounts and calendars. It offers simple ways to synchronize the different calendars, which allows me to keep everything in view. I particularly like the booking page, which makes it a perfect place to manage everything related to my appointments. The initial setup process was super easy, as I could sign in with Gmail, for example, and the synchronization of the calendars is explained very clearly. In combination with Google and Outlook calendars, OneCal works perfectly to synchronize everything. Review collected by and hosted on G2.com.

The only thing I would personally like is for the app to allow setting the appointment to private. Review collected by and hosted on G2.com.

I work with multiple clients, and it has always been a challenge coordinating availability. While booking pages work well, they require my clients to remember that I (1) have a booking page and that (2) my availability in their internal system isn't reflective of my actual availability. Those hurdles lead to people just scheduling a time on an open slot, which causes conflicts.

OneCal solves this in the simplest way possible: By copying my calendar entries across my calendars, everyone gets to see my actual availability in the system they are already using. OneCal's booking feature handles availability for anyone who isn't part of an organization I'm already working with, fully covering my use cases.

OneCal allows you to select the level of information you share, which allows me to prevent clients' information from being shared with other clients. It's a great system and has already saved me hours of time by not having to reschedule meetings. Review collected by and hosted on G2.com.

Updated May 2026: While neither of these features has been added, I've found that I haven't used them enough in Calendly to justify the extra service. I've fully replaced Calendly with OneCal.

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As of August 2025, OneCal's booking feature isn't as mature as competitor products. It isn't the core feature of OneCal, so it doesn't make me any less likely to recommend OneCal. Specific features the booking feature lacks: Ability to limit the number of an events scheduled on a day (e.g., I can only schedule one off-site meeting per day) and creating one-off meeting links with custom availability. I expect these features to mature over time, but I haven't been able to 100% replace my Calendly subscription just yet. Review collected by and hosted on G2.com.

I primarily utilize OneCal to keep multiple calendars synced so that different organizations can see my shared schedule. Traditional calendar sharing will not allow other users to see exterior calendars making it nearly impossible to reschedule meetings without manually checking.

This one tool helps me manage tons of calendars effectively and my coworkers, clients, and companies can all keep track of my schedule in real-time as opposed to having to have me constantly backtracking on meetings. Review collected by and hosted on G2.com.

Overall there isn't a lot to dislike about OneCal. I think they could have a slightly better price scaling or segment there capabilities for users that care more about calendar sync versus booking links, etc.

They are also still a bit new from my persepective, but do have a solid platform and the growth I've seen so far gives me a great impression they will have a great continuous development cycle that will make this application one of the best for calendar management in the near future. Review collected by and hosted on G2.com.

OneCal is easily the best tool for cloning appointments across multiple calendars. I manage so many client calendars that it’s way too time-consuming to copy everything manually. With OneCal, I can automatically clone appointments and use my Teams/Office integration so meetings get scheduled appropriately and automatically. It’s not the cheapest tool in the industry, but in my experience it’s definitely the best. The also have a Discord group with the developers if you ever have UI / UX suggestions or need more direct support. Review collected by and hosted on G2.com.

I have not had any issues with OneCal. SOMETIMES the syncing goes slowly, but you can log into the portal and "Re-Run" and everything gets cleaned up. Review collected by and hosted on G2.com.

Really intuitive and simple interface - it takes a few minutes to set up, and then just runs in the background while you get on with your life. I haven't really had to think about it since I signed up more than a year ago, which is a good thing. Review collected by and hosted on G2.com.

I stopped recieving 2 step verification emails from OneCal because my email provider had marked them as spam. This was confusing, and I needed to reach out to OneCal to "whitelist" my own email again - seems like something that should be ironed out between OneCal and major email providers. Review collected by and hosted on G2.com.