Prismm is being retired — here's the timeline
If you plan events on Prismm (formerly AllSeated), your account has a deadline. Cvent acquired Prismm in April 2025, and the standalone platform is being wound down.
Per Cvent's own migration page:
| Date | What happens |
|---|---|
| May 13, 2026 | You're redirected to activate a Cvent Event Diagramming account |
| May 13 – Jul 8, 2026 | You can create and edit in both platforms |
| Jul 8 – Sep 30, 2026 | Prismm is edit-only for existing events — no new events |
| Oct 1, 2026 | Prismm becomes view and export only |
| Dec 31, 2026 | prismm.com access ends and support is switched off |
Existing users move to Cvent Event Diagramming (formerly Social Tables), keeping their permissions and email addresses.
⚠️ What does not come with you
This is the part worth acting on:
- Templates, favourites and object groups do not migrate. You rebuild them by hand.
- Events dated before January 1, 2022 had to be exported before activation, or they become inaccessible. Events from Jan 1, 2022 onward carry over.
- After October 1 you can still export, but you cannot edit. If you have live events to change, that's your real deadline — not December.
Do this today, whichever tool you end up choosing: open Prismm and export every floor plan, guest list and diagram you might want later. Export is free and available until December 31. Rebuilding a venue's floor plan from a screenshot is not.
Choosing a replacement
Be honest about which job you're replacing, because Prismm did two quite different things.
If you need photorealistic 3D venue tours
Cvent Event Diagramming is the intended destination and the closest match — 3D diagramming, venue sourcing, and the wider Cvent ecosystem. It's also where your migrated data already is, so the switching cost is lowest.
The catch is the commercial model. The Essential tier is free but capped at 1 user, 3 events, 2 diagrams per event and 150 attendees per list. The Professional tier is $199/month on a 12-month commitment. For a large venue or hotel with an existing Cvent relationship, that's normal. For an independent planner or a small venue running a handful of events a year, it's a steep jump from what Prismm cost them.
We're not going to pretend SeatPlanning replaces this. If immersive 3D walkthroughs are how you sell the room, go with Cvent or a dedicated 3D tool.
If what you actually used was the seating chart
Most Prismm users we hear from weren't using the 3D showroom features weekly. They were doing the everyday job: lay out the tables, seat the guests, chase the RSVPs, hand the venue and caterer a clean PDF.
That's what SeatPlanning is built for, and it's a much smaller, cheaper tool:
- Drag-and-drop floor plan — round and rectangular tables, areas for the dance floor, stage and bar, rotate and resize to match the real room
- Guest import from Excel or CSV, with custom fields for dietary needs, accessibility and "keep apart" notes
- Online RSVP collection with branded email invitations, feeding straight into the chart
- QR tickets and door check-in
- Team collaboration — invite your planner, your client or the venue, or share a link
- PDF and Excel export for the venue, caterer and stationer
There's a free builder with no account at all if you want to try laying out a room before committing to anything, and current plans are here.
One thing to check with us first: we don't currently advertise an automated Prismm import. Export your Prismm data regardless, then get in touch and we'll tell you honestly what we can and can't bring across.
Quick comparison
| Cvent Event Diagramming | SeatPlanning | |
|---|---|---|
| 3D photorealistic tours | ✅ | ❌ |
| 2D floor plan + seating | ✅ | ✅ |
| Guest import (Excel/CSV) | ✅ | ✅ |
| RSVP collection | ✅ | ✅ |
| QR check-in | ✅ | ✅ |
| Free tier | 1 user, 3 events, 150 attendees | Free builder, no account |
| Paid from | $199/mo, 12-month commitment | See pricing |
| Best for | Large venues, hotels, existing Cvent customers | Planners and venues who mainly need seating, guests and exports |
Pricing checked 17 August 2026 against each vendor's published information. Confirm before you buy.
What to do this week
- Export everything from Prismm — floor plans, guest lists, diagrams. Before October 1 if you still need to edit anything.
- Decide which job you're replacing — 3D venue sales, or seating and guest management. They have different answers.
- Trial the replacement on one real event before your next busy season, not during it.
- Rebuild your templates early. They don't migrate, and rebuilding them under deadline is how mistakes reach the venue.
