B4X

B4X is a suite of rapid application development tools for Android, iOS, desktop, server, and IoT projects. Its B4X language is described as a modern version of Visual Basic. The maker says B4A, B4J, and B4i projects can share 90%+ of their code through cross-platform libraries. B4A includes a GUI designer for multiple screens and orientations, with debugging over USB or a wireless bridge. B4J creates desktop interfaces, console programs, and server solutions for Windows, Mac, Linux, and ARM boards such as Raspberry Pi; B4R targets Arduino, ESP8266, and ESP32. The maker says compiled iOS, Android, Arduino, and ESP8266 applications are native and have no dependencies. B4A, B4R, and B4J are free, including for commercial use. Standard B4A and B4i licenses are $59, paid once per developer. B4i requires an Apple developer account costing $99 per year, an iOS 11+ device, and Windows 7 64-bit or a VM for its IDE.

B4X covers several development targets and includes free tools for Android, desktop, server, and IoT work. iOS development has additional account, device, and IDE requirements.

B4X may suit developers building across mobile, desktop, server, and IoT targets. Its free B4A, B4R, and B4J options may fit projects on Android, desktop, or supported IoT boards.

B4X is a family of programming tools for developers building mobile, desktop, server, and embedded-device software. It is best suited to programmers who want focused tools for several targets and substantial code reuse across mobile projects. Its broad free offering is a strong starting point, while iOS development brings extra costs and setup.

Overview

B4X divides development among B4A for Android, B4i for iOS, B4J for desktop and server applications, and B4R for microcontrollers. The maker describes compiled iOS, Android, Arduino, and ESP8266 applications as native and without dependencies. It also says B4A, B4J, and B4i projects can share more than 90% of their code through cross-platform libraries. That is an appealing proposition for developers targeting multiple platforms, though it relies on working within this family of tools rather than a single universal editor.

The B4X language is described as a modern version of Visual Basic; Java is also supported. Developers comfortable with either have a clearer reason to consider it than those seeking a toolkit centered on another language. Anywhere Software says it has specialized in mobile development since 2005.

Key features

Android and iOS

B4A provides a GUI designer for multiple screens and orientations, plus debugging over USB or a wireless bridge. Those options make interface work and device debugging more practical for Android developers. B4i covers iOS, but its requirements narrow the convenience: development calls for a $99-per-year Apple developer account, an iOS device running iOS 11 or later, and Windows 7 64-bit or a virtual machine for the IDE. The hosted Mac Builder supports projects up to 50 MB, a constraint to weigh for larger builds.

Desktop, server, and IoT

B4J creates desktop UI applications, console programs, and server solutions, with apps able to run on Windows, Mac, Linux, and ARM boards such as Raspberry Pi. That breadth makes it useful beyond mobile work, particularly for developers who want one suite spanning desktop and server targets. B4R supports Arduino, ESP8266, and ESP32; its setup instructions call for Arduino IDE v2 and Arduino CLI, so embedded development still involves those tools. B4R libraries are open source under the MIT license, with code on GitHub.

B4X includes a visual UI designer, emulator or simulator support, and app packaging. The maker says it answers email within 24 hours and directs technical questions to its forum.

Pricing

The free tools are unusually substantial for developers who can use their target-specific editions: B4A, B4R, and B4J each cost nothing, including for commercial purposes. These cover Android; Arduino, ESP8266, and ESP32; and desktop, server, and IoT development respectively. There is no free B4i plan in the listed plans, and no free trial.

Paid licenses are perpetual and per developer, and applications developed with B4A, B4i, or B4J are royalty free. B4A Standard and B4i Standard each cost $59, paid once and include two months of free upgrades. The Standard editions suit individual Android or iOS developers who need a paid license but do not need the longer upgrade period of Enterprise.

B4A Enterprise and B4i Enterprise each cost $119, paid once and include two years of free upgrades. For iOS, B4i Standard + Hosted Mac Builder costs $85, paid once, while B4i Enterprise + Hosted Mac Builder costs $145, paid once; each includes one year of hosted builder service, with two months or two years of free upgrades respectively. These bundles may suit developers who want the hosted build service, but do not remove the separate Apple developer account requirement.

B4A Site costs $599, paid once, includes two years of free upgrades, and covers up to 30 developers on a single site. It is the team option; the per-developer licenses are a better fit for individual developers. Paid licenses are one-time purchases, but the stated upgrade periods are limited, so they should not be mistaken for ongoing free upgrades.

Platforms

B4X covers Android and iOS on mobile, and Windows, macOS, and Linux for desktop. B4J apps can also run on ARM boards such as Raspberry Pi, while B4R targets Arduino, ESP8266, and ESP32. The platform spread is a strength for developers working across device types, though iOS has notably more prerequisites than the free Android, desktop, and IoT tools.

Who it's for

B4X makes the most sense for developers who want to build across mobile and desktop or server targets, particularly if sharing code among B4A, B4J, and B4i is valuable. Android, desktop, and IoT developers can begin with free tools, including for commercial work. Developers focused on iOS should account for the Apple fee, device requirement, Windows-based IDE setup, and hosted builder size limit before committing. Teams seeking a single-language environment outside Visual Basic-style B4X or Java may be better served elsewhere.

Pros and cons

• Pros: Free B4A, B4R, and B4J can be used commercially, lowering the entry cost for Android, desktop, server, and IoT work.
• Pros: The maker says B4A, B4J, and B4i can share more than 90% of their code, which may reduce duplication for cross-platform mobile projects.
• Pros: Perpetual paid licenses are royalty free for applications developed with B4A, B4i, or B4J.
• Cons: iOS development requires a $99-per-year Apple developer account, an iOS 11+ device, and Windows 7 64-bit or a VM for the IDE.
• Cons: The hosted Mac Builder is limited to projects up to 50 MB, which may rule it out for larger projects.
• Cons: Paid licenses include free upgrades only for a stated period, and licenses are per developer except for the site plan.

Alternatives

Godot Engine is a free, open-source game engine with no contracts or hidden fees; choose it when game development is the priority. Monaca offers a free cloud IDE plan with a debugging tool, three projects, and three remote builds per 24 hours, plus online community support; it is an option for developers who want a cloud IDE and can work within those caps.

AIDE is an Android-only freemium alternative, while C++Builder offers a free Community Edition as well as paid plans. Codename One has a free plan with 100 cloud build credits per month, eight credits per iOS cloud build, and an 8.5 MB user JAR limit. Defold is free forever with no licensing, royalty, or runtime fees. DroidScript is free to download, with optional paid plugins and donations. Felgo offers a free Personal plan for annual turnover under €50k and a Startup plan at €79 a month, billed annually. For more options, browse Mobile Development IDEs.

Verdict

Choose B4X if you want free commercial tools for Android, desktop, server, or IoT development, with a path to share code across mobile targets and perpetual paid licenses when needed. Its strongest case is breadth without an upfront cost for several targets. Look elsewhere if iOS requirements are a poor fit or if you need a toolkit built around a different programming language.