AllSeated vs Altessa: Wedding Floor Plan and Seating Chart Tools

AllSeated, which became Prismm in 2024 and was bought by Cvent in 2025, is built for venues and professional planners who run hundreds of events, and Altessa is built for a couple running one, so the right tool depends on which of those you are. I built Altessa, so read the Altessa half with that in mind. The Prismm half comes from Prismm's and Cvent's own pages as of October 2026, and I've tried to give it full credit, because it is a serious piece of software.

Side by side

Who each one was built for

Prismm's own story page traces it from AllSeated's 2014 launch through 3D in 2018, a German acquisition in 2021, and the Prismm rebrand in 2024. Cvent's press release from April 2025 announcing the acquisition says more than 5,500 event venues, hotels, planners, and vendors rely on it. Its wedding page calls it planning software for brides and professionals alike, but the couple in that sentence is the planner's client: the person the planner shares the diagram with, comments with, and walks through the 3D tour with. The free plan on Cvent's Prismm pricing page is sized for a vendor trying it out, one user and three events, and the paid plans are 1,500 or 3,500 dollars a year, which is a tool a venue amortizes across a season.

Altessa is the other end of that. One couple, one wedding, one room. It assumes nobody on the team has drawn a floor plan before, so the wizard asks for the room shape, the guest count, and the table shape, generates a first layout, and lets you drag from there. If your venue or planner already uses Prismm, you'll likely never need Altessa's layout builder, and you should ask them for the diagram; it will be excellent. If nobody is drawing the room for you, which is the case at most restaurant, brewery, barn, and backyard weddings I filmed, you need something built for you to draw it.

True-scale room layouts, table shapes, and seating

Both are to scale. Prismm says everything's to scale and that it holds more than 150,000 venue floor plans, which means there's a decent chance your venue's room is already in it if your planner has an account. Its 3D is the showpiece: photorealistic renders, virtual walkthroughs, digital twins of real spaces. Nothing in Altessa competes with that, and I'm not going to pretend otherwise. Altessa is 2D, drawn in feet or meters, with the option to import the PDF or image the venue handed you instead of redrawing it.

Where Altessa is specific is the tables and the seats. The palette has rounds from 4 to 7 feet, 6 and 8 foot banquets, and a 10 foot king's table, each with a seat count you can edit, and guests are seated at a specific seat by dragging them from the guest list onto the canvas. Prismm's guest list carries RSVP status, party size, and meal choice, and its support center has an article on assigning guests to seats; its product pages don't list the table shapes, so I can't compare that line. The seating method I'd use in either tool is here.

Sharing the layout with your venue and vendors

Prismm wins on live collaboration, and it should, because collaboration between a planner, a venue, and a caterer is the job it was built for. A shareable link, comments directly on the layout, and changes that appear in real time for everyone on it. If you have a planner, that's the workflow you want.

Altessa's sharing is a file. Download a PDF with the floor plan and a card per table, send it to the venue, the caterer, and the rental company, and send the day-of timeline to each vendor from the run of show. The whole plan exports as a ZIP of spreadsheets with no email gate, so the venue gets the floor plan and the caterer gets the list by table without either needing an account. For a couple with no planner, a PDF the venue can print is the thing that actually gets taped to the wall on the morning of, and I've watched that happen more times than I've watched anyone open a shared link.

Where Altessa fits

If you're a venue or a planner, Prismm is the better tool and it isn't close; it has the 3D, the venue library, and the collaboration, and it's priced for a business. If you're a couple drawing your own room because the venue doesn't do it for you, Altessa is the one built for that, and the floor plan comes attached to the rest of the plan: a budget with every vendor's deposits and balances, a timeline dated to your wedding that pushes to Google Calendar, a guest list with one row per person, and a run of show. Premium is 120 dollars once, and you can start free and draw the room before you pay. Paper, a spreadsheet, and an app each have a guest count where they break; under fifty guests in a restaurant, paper is still the right call.

Questions people ask

Is AllSeated still around?

AllSeated rebranded to Prismm in January 2024, and Cvent acquired Prismm in April 2025. The product continues under the Prismm name, and its own site says Prismm is now part of Cvent.

Can couples use AllSeated or Prismm for free?

There is a free plan on Cvent's Prismm pricing page with one user, three events, two diagrams per event, and 150 attendees per list. It's sized for a vendor trial; paid plans are 1,500 or 3,500 dollars a year.

Is Altessa's floor plan to scale?

Yes. You draw the room in feet or meters or import the venue's PDF, and the tables are real sizes from 4 foot rounds to a 10 foot king's table, with seat-level assignment. The layout builder is in the Premium tier, 120 dollars one time.

What is the best wedding floor plan tool for couples without a planner?

One built for a single wedding, with a to-scale room, real table sizes, seating from your own guest list, and a PDF the venue can print. That is what Altessa's layout builder is. Professional tools like Prismm are stronger for planners and venues running many events.

Armin Korsos is a filmmaker who spent nine years shooting weddings before building Altessa (altessa.studio), an all-in-one wedding planning workspace that replaces the spreadsheet.