Prismm (formerly AllSeated) · product sunset
Prismm is shutting down — the SemiChair alternative for seating plans
Cvent is discontinuing Prismm on a published timeline. For venues, that means the tool the team built seating plans with every week needs a successor — and the schedule is already set.
Arriving from our letter? The offer in it stands: send us 1–2 floor plans and we will set up your rooms free of charge.
The timeline according to Cvent
since 8 July 2026
no new events in Prismm
from 1 October 2026
read-only access
31 December 2026
access ends
Note
Events dated before 1 January 2022 are no longer accessible in Cvent Event Diagramming
What transfers — and what doesn't
Cvent automatically migrates your data to its own tool, Cvent Event Diagramming — nobody is left without their floor plans. Part of your work, however, has to be rebuilt wherever you go:
Migrated automatically
- Base floor plans
- Room configurations
→ to Cvent Event Diagramming, with no action on your part.
Has to be rebuilt
- Templates
- Favourites
- Groups
→ by hand, in any successor tool.
So the rebuild is unavoidable. That makes now the natural moment to decide which tool it happens in.
What SemiChair is — and what it's not
SemiChair is a fast, precise 2D seating and room planning tool for venues: your real rooms are stored to scale, seating plans take minutes and are accurate to the centimetre, with A4 print & PDF export for you, your clients or the setup crew — hosted in Germany and Austria, in the browser with no installation.
We set up your rooms free of charge
Step 1
Export floor plans
Export 1–2 floor plans from Prismm as JPG or PNG — exporting an empty room gives you the floor plan.
Step 2
Send them to us
By email to hallo@semichair.de or via the contact form at the bottom of this page.
Step 3
Rooms set up to scale
We set up your rooms in SemiChair to scale, free of charge. You rebuild the seating once — that's exactly what the tool is made for.
or directly to hallo@semichair.de
Try it yourself — no sign-up
Right in the browser: you'll have placed your first chair within 30 seconds.
Who works with SemiChair
Venues from municipal halls to five-star hotels in Germany, Austria and Switzerland work with SemiChair — The first venue has already switched from Prismm to SemiChair.
Each plus a one-time setup — your first 1–2 rooms are set up free of charge through the offer above. Full plan details are in the pricing comparison on the home page.
Common questions about switching
01 What happens to my old plans?
Cvent automatically migrates base floor plans and room configurations to Cvent Event Diagramming. From 1 October 2026 Prismm is read-only; on 31 December 2026 access ends. Events dated before 1 January 2022 are no longer accessible in Cvent Event Diagramming.
02 Does SemiChair import my seating plans from Prismm?
No — honest answer: only floor plans as images (JPG/PNG) are taken over, which we set up in SemiChair to scale. You rebuild the seating once; that's exactly what the tool is made for.
03 Do I need to install anything?
No. SemiChair runs in the browser — no installation, on any up-to-date computer.
04 Where is the data hosted?
Hosting is in Germany and Austria. On request, SemiChair can run on your own infrastructure — your plans never leave your network. Talk to us about this as part of an Enterprise conversation.
Let's talk about your event
Do you have questions or would you like a guided walkthrough? Get in touch – we look forward to your enquiry.
- hallo@semichair.de
- Phone
- +49 (0) 176 76 288 021
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