Apps & SaaS 
Which agency should you choose for web application development in Belgium?
Gaspa Agency leads our October 2026 top 10 for its combination of product discovery, design and development in Brussels. Digital Unicorn takes second place, followed by Deuse and icapps. Choose your partner by matching its work to your customer portal, SaaS, business tool or connected platform.
Key points for your project
- 01Describe users, tasks and data before selecting a technology.
- 02Compare the same first release, including tests and recurring costs.
- 03Ask for a demonstration, source access and a maintenance plan.
An editorial selection published by Gaspa. Read our methodology
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1. Gaspa Agency — web applications, SaaS and business software in Brussels
Based in Brussels, Gaspa Agency combines product strategy, UX/UI design and development to build custom web applications. Customer portals, SaaS platforms, CRMs and internal tools start with business use cases, connecting the interface, data and integrations required to run the product.
For a business launching or modernising a product, continuity is a useful distinction: discovery, design and delivery progress within the same team. Clients can discuss functional priorities and their technical implications throughout the project.
The Enneco project illustrates this approach through a CRM for construction businesses, spanning art direction, discovery, design and development. Gaspa also supports institutional projects such as ECSDA, with a WordPress platform organising members, publications and events.
Specialties and project fit
- Location: Brussels, Belgium.
- Specialties: web applications, SaaS platforms, CRM, UX/UI and integrations.
- Best suited to: businesses and product owners looking for support from discovery through ongoing development.
Two projects illustrating Gaspa’s approach
Sources consulted
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2. Digital Unicorn — web applications and digital products for Brussels
Digital Unicorn offers web application, SaaS and combined web/mobile product development. Its Brussels page presents services from UX/UI through development and maintenance. Book Village is among the web and mobile references highlighted on its website.
Specialties and project fit
- Market: services aimed at Brussels.
- Specialties: web applications, SaaS, UX/UI and mobile development.
- Best suited to: products sharing functionality across a web interface, back office and mobile application.
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3. Deuse — custom web platforms and business integrations
Deuse lists offices in Liège, Brussels and Hasselt. It develops custom platforms and tools connected to business management systems. Its Vet’Ardent case study presents a tablet-based web application for veterinarians making field visits.
Specialties and project fit
- Locations: Liège, Brussels and Hasselt.
- Specialties: web platforms, business software and integrations.
- Best suited to: businesses whose web project needs to reflect a specific operational workflow.
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4. icapps — architecture, web applications and connected systems
Antwerp-based icapps combines strategy, architecture and digital product development. Its services include responsive web applications, content and administration portals, and integrations between systems.
Specialties and project fit
- Location: Antwerp.
- Specialties: digital products, architecture, portals and integrations.
- Best suited to: organisations whose application must fit an information system made up of several tools.
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5. Nubios — business analysis and web platform development
Located in Awans in the Liège region, Nubios presents a custom approach combining analysis, UX/UI, development and support. Its portfolio includes a project for Mouscron assessing sustainable development goals, described as a PWA.
Specialties and project fit
- Location: Awans, Liège region.
- Specialties: analysis, custom software and web applications.
- Best suited to: businesses that need to formalise requirements and business rules before building a platform.
Sources consulted
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6. Spatie — Laravel web application development
Spatie, in Antwerp, focuses on Laravel and PHP. It uses tools including React and Livewire for interfaces and contributes to open source. Its services cover analysis, technical foundations, testing and short development cycles.
Specialties and project fit
- Location: Antwerp.
- Specialties: Laravel, PHP, APIs and React or Livewire interfaces.
- Best suited to: applications for which Laravel fits the requirements or already forms part of the technical environment.
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7. November Five — product strategy and digital platforms
November Five, headquartered in Antwerp, designs and develops digital products. Its Le Pain Quotidien case study describes an international web platform built with Next.js and DatoCMS to bring several markets into a shared digital system.
Specialties and project fit
- Location: headquarters in Antwerp.
- Specialties: digital product design and web platforms.
- Best suited to: brands and organisations coordinating a digital experience across markets or languages.
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8. VR Agency — web development and custom platforms
Brussels-based VR Agency offers business platforms, SaaS, CRM and ERP development, alongside API integrations. Its portfolio includes a custom platform for Hertoghe Medical School.
Specialties and project fit
- Location: Brussels.
- Specialties: business platforms, SaaS, CRM/ERP and API integrations.
- Best suited to: businesses and institutions seeking a custom platform connected to their existing tools.
Sources consulted
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9. EPIC — design, web platforms and interactive experiences
Liège-based EPIC combines strategy, branding and digital experience development. Its Elantis case study describes merging two websites and digitising the credit application journey, connecting brand experience with an online service.
Specialties and project fit
- Location: Liège.
- Specialties: design, websites, applications and interactive experiences.
- Best suited to: projects where brand identity and the usability of a customer journey are central.
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10. Mister Jekyll — web applications and responsive platforms
Mister Jekyll is a Namur agency covering functional analysis, design and web development. Its portfolio features Taste Tomorrow for Puratos, including a custom back office for managing events and invitations.
Specialties and project fit
- Location: Namur.
- Specialties: web applications, responsive websites and e-commerce.
- Best suited to: businesses and institutions combining content, user journeys and custom functionality.
Sources consulted
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The top 10 web application agencies in Belgium at a glance
The right partner depends on the product you need to deliver. This overview brings together agency specialties and references or services to review before your first conversations.
| Agency | Location or target market | Specialties | Project or services to explore |
|---|---|---|---|
| 1. Gaspa Agency | Brussels | Product discovery, UX/UI, web applications and business tools | Enneco case study: CRM design and development |
| 2. Digital Unicorn | Services aimed at Brussels | Web applications, SaaS and web/mobile products | Book Village: web marketplace presented on its website |
| 3. Deuse | Liège, Brussels and Hasselt | Custom platforms and business integrations | Vet’Ardent: a web application for field visits |
| 4. icapps | Antwerp | Digital products, architecture and integrations | Public web, portal services and portfolio to examine |
| 5. Nubios | Awans, Liège region | Business analysis, platforms and web applications | Mouscron: a project described as a PWA |
| 6. Spatie | Antwerp | Laravel-focused web development | Technical services and public open source code |
| 7. November Five | Antwerp | Product strategy and web platforms | Le Pain Quotidien: international web platform |
| 8. VR Agency | Brussels | Business platforms, SaaS and API integrations | Hertoghe Medical School: custom platform |
| 9. EPIC | Liège | Branding, design and applications | Elantis: digital credit application journey |
| 10. Mister Jekyll | Namur | Analysis, web applications and responsive design | Taste Tomorrow: back office and events |
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What kind of web application do you need?
A web application lets users complete tasks in a browser: submit a request, manage a case, book, collaborate or monitor activity. A brochure website mainly presents content. SaaS describes delivering software as a service; a PWA adds installation and app-like capabilities, depending on the implemented features and browser.
These labels do not determine project complexity. Describe the users, permissions, data and actions in the first release. If device features or offline use are essential, test them on target devices before deciding between web, PWA and a mobile application.
| Application type | Example features | Key point to clarify in the quote |
|---|---|---|
| Customer or partner portal | Login, requests, documents, status updates | Data separation and permissions between organisations |
| Business tool / CRM | Cases, approvals, scheduling, reporting | Business rules, migration and team adoption |
| SaaS platform | Organisation accounts, plans, billing | Customer separation, administration and operations |
| Marketplace / booking | Catalogue, availability, orders, payments | Transaction rules and provider integrations |
| PWA / field use | Installation, data entry, some offline access | Feature compatibility and synchronisation testing |
| Application redesign | New journeys, modernisation, data migration | Initial audit and business continuity during transition |
Find the service that matches your needs
Sources consulted
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What services should a web application development agency provide?
A web application agency turns a business need into a product people can use every day. Its role covers product decisions, interfaces and engineering, followed by the conditions for maintaining and improving the application.
Six parts of a complete engagement
- 01
Discovery and priorities
Goals, users, journeys and the first release to deliver.
- 02
UX/UI and prototyping
Interfaces and clickable prototypes to validate usage.
- 03
Web and SaaS development
Interfaces, business logic, accounts and administration.
- 04
APIs and integrations
Connections to CRM, ERP, payments and data.
- 05
Testing and launch
Acceptance, mobile compatibility, performance and deployment.
- 06
Maintenance and security
Updates, incident handling and future releases.
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From idea to launch: how does a web project work?
At Gaspa, product, design and technology share the project context. Decisions become easier to follow when each stage produces something to review: prioritised scope, prototype, testable release and an application ready for users.
The stages to look for in a proposal
- 01
1. Understand the need
Describe the journey, intended users and constraints.
- 02
2. Validate scope and design
Prioritise a first release and test the prototypes.
- 03
3. Build and connect
Develop functionality and data exchanges.
- 04
4. Test and launch
Verify scenarios, prepare migration and support launch.
- 05
5. Measure and improve
Gather feedback, fix issues and plan new features.
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How much does a web application cost in Belgium, and how long does it take?
There is no single price for a web application in Belgium. A form connected to an existing tool and a SaaS with multiple organisations, subscriptions and access rules require different work. Budget for discovery, data, interfaces, integrations, testing and launch.
Request two views of the estimate: the cost of a usable first release and the cost of operating it for twelve months. Hosting, licences, APIs, payments, backups and maintenance should have explicit assumptions. A daily rate alone does not establish total cost.
For timing, ask for a schedule that separates analysis, prototype, development, acceptance testing, migration and launch. Identify your own approvals and external dependencies. A useful deadline rests on scope and availability assumptions rather than the number of screens alone.
A proposal you can compare
- ✓Written user journeys, exclusions and acceptance criteria.
- ✓An estimate by stage, with data and integration assumptions.
- ✓Recurring costs and arrangements after delivery.
Points to clarify
- ×One total without a defined first release.
- ×A deadline that omits approvals or access to APIs.
- דMaintenance included” without defined tasks and support arrangements.
Give agencies the same brief
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How do you choose a web agency in Brussels, Wallonia or Flanders?
Shortlist two or three agencies with references close to your use case. Proximity can help with workshops, but check the people who will deliver the work and the working languages. For a Belgian product, specify French, Dutch and English requirements for interfaces, content and support.
Discuss a real journey rather than a list of frameworks. Using a sample case or order, the agency should explain what happens when something fails, who sees which data and how the team will verify the result.
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Security, maintenance and handover: what to plan before launch
For an application handling customer or team data, ask how authentication, permissions, user input and logging will be verified. OWASP ASVS can help agree on testable security controls. The word “secure” in a proposal does not describe the scope or results of testing.
Assign responsibility for updates, monitoring and incidents. Test backup restoration and clarify access to repositories, hosting and third-party services. For an existing application, review the code and data before deciding to rewrite everything.
Plan the next stages of the project
Sources consulted
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Selection criteria for this October 2026 top 10
This selection brings together agencies located in Belgium or offering services aimed at the Belgian market. It considers their web development services, presented projects and combination of design, engineering and ongoing support. Official sources were reviewed on 25 October 2026 and are linked beneath each profile.