The verdict in three sentences
Migrating a Bubble app to custom code costs between GBP 30,000 and 78,000 (about EUR 35,000 to 90,000) in London in 2026, over 3 to 5 months including data migration. It only pays off once at least two trigger thresholds are crossed: degraded response times, a Bubble bill inflated by workload units, or a funding round where investors require code ownership. Below those thresholds, optimising the existing Bubble app costs ten times less.
The thresholds that justify migrating
The right call does not depend on user count alone. It depends on the combination of signals below, observed on matching platforms between 1,000 and 10,000 active users.
| Signal | Green zone (stay on Bubble) | Red zone (migrate) |
|---|---|---|
| Load time of key pages | Under 2 s | Over 4 s at peak |
| Bubble plan + workload units | GBP 100 to 350 per month | Over GBP 1,000 per month and rising |
| Scheduled workflows and APIs | Fewer than 20 backend workflows | Over 80 workflows, frequent timeouts |
| Monthly active users | Under 2,000 | Over 5,000 growing 15 % per month |
| Investor requirements | Pre-seed | Seed or Series A with technical due diligence |
| Business needs | CRUD and simple payments | Matching algorithm, real time, native mobile app |
With 2,000 users and some slowness, most London platforms sit in the amber zone: a Bubble performance audit (GBP 1,700 to 4,300) can push the migration back 6 to 12 months.
What the rewrite costs
| Item | Small platform | Mid-size platform | Complex platform |
|---|---|---|---|
| Audit and specs from the Bubble app | GBP 2,600 | GBP 4,300 | GBP 6,900 |
| Front and back end (Next.js, Node, PostgreSQL) | GBP 19,000 | GBP 32,700 | GBP 50,000 |
| Data and user account migration | GBP 2,600 | GBP 4,300 | GBP 6,900 |
| Payments, email, integrations | GBP 3,400 | GBP 5,200 | GBP 7,800 |
| QA, cutover and parallel run | GBP 2,600 | GBP 3,500 | GBP 6,400 |
| Total | GBP 30,200 | GBP 50,000 | GBP 78,000 |
| Timeline | 3 months | 4 months | 5 months |
The underestimated item is data migration: Bubble exports CSV files without hashed passwords. You need a password reset by magic link or email login, and you must test that relationships between tables come across intact.
Costs after cutover
Once on custom code, hosting a 2,000 to 10,000 user platform costs GBP 70 to 260 per month (managed database, server, storage). Ongoing development runs GBP 700 to 2,200 per month depending on release pace. The main gain is not the hosting bill: it is feature velocity and the value of the technical asset at fundraising time.
Mini case study
Tom, founder of a London platform matching tradespeople with property managers, has 2,300 users. His Bubble bill rose from GBP 300 to GBP 1,200 per month in a year because of workload units, and the search page takes 5 seconds to load.
- Option A, stay on Bubble: audit at GBP 3,500, bill stabilised at GBP 780 per month. 24-month cost: 3,500 + 18,720 = GBP 22,220.
- Option B, migrate: mid-size platform at GBP 50,000, hosting GBP 130 and maintenance GBP 1,030 per month. 24-month cost: 50,000 + 27,840 = GBP 77,840.
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Option B costs GBP 55,620 more over two years. It is only justified because Tom is preparing a GBP 700,000 seed round and his matching algorithm does not fit in Bubble. Without those two factors, option A was the right choice.
FAQ
Can we migrate gradually instead of rewriting everything?
Yes. You can extract the back end and API first (GBP 13,000 to 26,000) while keeping the Bubble front end for a few months. That lowers cutover risk but extends double billing.
Will users have to create new accounts?
No, accounts and data are migrated. Only passwords must be reset, usually via a link emailed to 100 % of users the day before cutover.
How long is the app offline?
With a well-prepared cutover, 2 to 6 hours on a Sunday morning. A 1 to 2 week parallel run lets you roll back if needed.
Is SEO affected?
It usually improves, because Bubble renders pages poorly server-side. Keep URLs or plan 301 redirects for 100 % of indexed pages.
What maintenance budget should we plan?
GBP 700 to 2,200 per month for fixes and new features, plus GBP 70 to 260 of hosting.
Let's scope your project. Share read access to your Bubble editor and your traffic figures, and we will tell you whether to optimise or migrate, with a scope and a cutover plan. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
