The verdict in three sentences
A 15-year-old Delphi or WinDev application maintained by one developer is an operational risk, not just a technical topic: if that person leaves or falls ill, invoicing or production stops. Migrating to the web costs, as a 2026 order of magnitude in Montreal, between CAD 60,000 and 165,000 (about 40,000 to 110,000 EUR) over 3 to 8 months. The most underestimated item is data migration from Firebird, Paradox or HFSQL, not building the screens.
What drives the budget
A typical SME desktop app has 80 to 300 forms, a database of 50 to 200 tables and printed reports built up over the years. Cost depends less on screen count than on business logic buried in the code: pricing calculations, discount rules, accounting exports.
| Application size | Forms | Tables | 2026 order of magnitude (CAD) | Duration |
|---|---|---|---|---|
| Small | 40 to 80 | 20 to 50 | 60,000 to 82,000 | 3 to 4 months |
| Medium | 80 to 160 | 50 to 120 | 82,000 to 120,000 | 4 to 6 months |
| Large | 160 to 300 | 120 to 200 | 120,000 to 165,000 | 6 to 8 months |
| With mobile module | + 15 to 30 screens | Unchanged | + 15,000 to 30,000 | + 1 month |
| With connectors (accounting, EDI) | Unchanged | Unchanged | + 7,500 to 22,000 | + 2 to 4 weeks |
| With complex reports | + 30 to 60 reports | Unchanged | + 6,000 to 15,000 | + 2 weeks |
On the other side of the scale, a Delphi Professional licence runs around CAD 2,500 to 3,500 per developer seat plus yearly updates, and hiring a Delphi developer in Montreal is slow because the talent pool keeps shrinking. For an SME, a medium-complexity web application falls in Kolonell's 4M to 7M FCFA band (6,100 to 10,670 EUR), a complex one in 7M to 15M+ FCFA (10,670 to 22,870+ EUR), with maintenance from 35,000 to 120,000 FCFA per month.
The risks and how to neutralise them
Migrations rarely fail because of technology. They fail because nobody documented what the old application really does, and because users discover the gaps too late.
| Risk | Warning sign | Countermeasure | Cost of countermeasure |
|---|---|---|---|
| Undocumented business rules | The developer "knows" but wrote nothing | 2 to 4 weeks of reverse engineering | CAD 6,000 to 12,000 |
| Inconsistent legacy data | Duplicates, repurposed fields | Cleaning scripts and gap reports | CAD 4,500 to 13,500 |
| User rejection | Keyboard habits, shortcuts | Workshops and mock-ups from month 1 | Included in scoping |
| Failed cutover | Wrong invoices on day one | 1 to 2 months parallel run | Partial double entry for 1 to 2 months |
| Original developer leaving | End of contract, retirement | Knowledge transfer contract | CAD 3,000 to 7,500 |
| Scope creep | "While we're at it" | Lot 1 like-for-like, changes in lot 2 | Free, discipline |
The recommended sequence: scoping and reverse engineering (3 to 5 weeks), module-by-module development with a dry-run data migration at each iteration, then parallel running where old and new apps operate on the same data. Final cutover happens only after a month-end close with zero discrepancies. In Quebec, also check that the new system meets Law 25 privacy requirements for personal data.
Mini case study
Marc, owner of an electrical supply distributor near Montreal, runs quotes, orders, stock and invoicing on a Delphi application built in 2011. One external developer maintains it for CAD 27,000 a year, licences included. The migration is priced at CAD 108,000 for 130 forms and 90 tables. The new web application costs CAD 13,500 a year in maintenance and hosting, saving CAD 13,500 a year. The real gain lies elsewhere: one week of blocked invoicing means CAD 180,000 of delayed revenue. If the risk of such a block is estimated at once every 3 years, the migration is justified on continuity alone. This scenario is illustrative.
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FAQ
Can we keep WinDev and move to WebDev, or Delphi to a web framework from the same vendor?
It is possible and faster, about 30 to 40% cheaper. But you stay tied to one vendor ecosystem and a small developer pool.
Is legacy data 100% recoverable?
Technically yes, through export or ODBC access. In practice, 2 to 5% of records need manual correction because fields were repurposed over time.
How long does parallel running last?
Usually 1 to 2 months, so at least one full month-end close. No clean close, no cutover.
Should we migrate everything at once?
No, splitting by module (stock, then orders, then invoicing) reduces risk. Each lot goes live in 6 to 10 weeks.
Will the web app work offline?
Yes for selected screens, through a PWA with sync. Allow CAD 12,000 to 22,000 more depending on offline data volume.
Let's scope your project. Describe your desktop application (forms, tables, users) and we will price the migration scope, indicative budget and 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.
