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Prismm is an event planning software leader in the digital twin technology space.

Explore the infinite possibilities of space with online event planning software from Prismm (formerly Allseated)

The Difference is Spatial Design Technology


Prismm changes how organizations and people connect, collaborate, and transact across virtual spaces, elevating the standard in spatial design technology. Beyond simple event planning software, Prismm is a platform designed to create and deliver full, dynamic experiences.


A digital representation of an empty room; displaying how one can showcase their space.

Showcase your space

No calendar, no chaos.

Take the stress out of scheduling onsite visits in between events. Prismm provides a dynamic digital twin so clients can tour your space when they want to, wherever they are. Change layouts effortlessly and add rich content overlays — marketing and personalizing your space has never been this simple.  

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A collage of images to represent how you can sell your space: a woman with folded arms smiling confidently, two empty rooms, and a cityscape.

Sell your space

There wasn’t anything to compare with pure imagination. There is now.

Don’t make your clients rely on their imagination to bring your space to life. With Prismm’s immersive 3D technology and event software, you can highlight unique features of your space and build their vision in real time, giving them confidence in your capabilities. Don’t dream it. Experience it.  

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A stylized image of the Prismm platform dashboard.

Design and plan your event

One platform to rule them all.

With one intuitive centralized workspace, online event planning is simple. Create immersive 2D or 3D layouts with accurate-to-the-millimeter floor plans. Collaborating, creating, designing, and making changes is as easy as 1, 2…done. If you’re an event planner, software like ours is the obvious way to work smarter, not harder.

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Why Choose Prismm

Space is not the final frontier

Prismm’s online event planning tool virtualizes and visualizes spaces, capturing them in precise 2D and rich, immersive 3D for customers to explore, design, and experience the space dynamically.

Time is on your side

With high client demand for events and labor shortages in the industry, time is of the essence. With the Prismm platform, even last-minute changes can be updated in minutes, saving time, money, and sanity for everyone and setting a new bar for online event planning. Maximize your resources and minimize stress with our online event planner.

Go with the flow

For any event experience or occasion to be successful, the flow throughout the space must be perfect. Prismm captures the transitions, changes, and interactions that occur in a space or spaces — streamlining workflow throughout every step of the experience.

Change space

The Prismm Platform’s dynamic display means you can effortlessly change how the digital twin of your space looks, tailoring it to the specific needs of your clients and elevating the standard in spatial design technology. See for yourself.
Four images showing how Prismm provides immersive 3D spaces to explore.
A stylized image showing an empty room in the Prismm platform, formerly known as Allseated.
Multiple related images from an event showing how Prismm streamlines the workflow throughout every step of an experience.
A collage of images representing how an event goes from planning to execution.

Trusted by marquee brands around the globe

Customer Testimonials

"With Allseated (now Prismm Platform) our clients’ experience was enhanced, being able to navigate easily on our venue spaces, with immediate visualisation of their set-up desires. Personalisation became instant, selling efficiency increased, all the involved parts are now staying easily in permanent contact.”

Iulia Popescu
Director Of Event Management, JW Marriott Bucharest
Scandic logo

“Including Allseated (now Prismm Platform) as part of our selling process has given us the opportunity to show current and prospective clients our spaces in various setups, giving them the ability to envision their event with us before it takes place, without having them come onsite. This sets us apart from our competitors.”

Isabel Sibürge
Director of Convention Sales Germany, Scandic Hotels
AOO events logo

"Designing a space like this is very much like designing in a regular ballroom, you're sitting in the space, you have to think about egress, you have to think about crowd flow. This really parallels real life."

David Merrell
CEO & Creative Director, AOO Events
Twickenham logo

"As a collective, we love using Allseated (now Prismm Platform)! Given that we have so many rooms with so many features, shapes, and sizes, it is great to have a tool to help us change our configurations quickly and easily."

Shirene Lalmahomed
Conference & Events Coordinator, Twickenham Stadium


  • Event planning software, like Prismm, empowers you to virtually visualize, design, and refine your event space using a digital twin of your venue. This authentic simulation allows you to experiment with every element — from chair styles to bouquet colors — providing a real-life preview of how each decision impacts your event’s aesthetic and flow. For event professionals, Prismm is an indispensable tool that turns vision into virtual reality, covering the entire event lifecycle.

  • Join thousands of event planners worldwide who benefit from our extensive database of venue templates. It’s not just about boasting—it’s about convenience. Start by creating your event in Prismm and select your venue from our preloaded options. If your venue isn’t listed, don’t worry; we’ll guide you through the simple process of uploading images and specifications to craft your venue’s digital twin.

  • Showcasing your event design has never been easier. Prismm’s popular sharing feature generates a link to your event layouts and diagrams, which you can send via text, email, or direct message. This seamless sharing enhances collaboration and client engagement, making it a breeze to bring your vision to stakeholders and team members alike, ensuring a successful event.

  • If you’re new to online event planning or to Prismm, we understand you might want to try before you fully commit. That’s why we offer a free trial, showcasing why we are confident in our claim as the best event management software in the business. Contact our customer service team today, and we’ll tailor a trial package that lets you explore all the benefits of our innovative event management solution.

  • While there may be other software that seems similar, not all event management platforms are on par with Prismm. Our distinguishing features include a user-friendly interface, dedicated support team, collaboration-enhancing capabilities, and exceptionally realistic digital twins. You’re already here—so consider your search for the ultimate event planning software complete.

  • Prismm is versatile enough to cater to any gathering, transforming any venue from ballrooms to conference centers into a perfectly tailored event space. Our event planner tools streamline the process from concept to final design, ensuring your next event space is not only functional but also inspiring.

  • Forget the hassle of in-person meetings for minor changes. Our event software enables real-time collaboration, allowing your event team—from marketers to florists—to access, modify, and comment on designs. This unified approach ensures aligned decisions and contributes to the flawless execution of your event. The key to successful event planning begins here.

  • The event planning world moves fast, and so does our support team. Available 24/7 via live chat, we respond instantly to help with any inquiries. For more complex issues, we escalate them promptly as you navigate the nuances of event planning online, ensuring you always have expert support at your fingertips.

Are you ready to explore?


Get a demo or create an account