Hew Playground
Code, Run & Learn Hew
Free · Designed for iPad. Not verified for macOS.
Hew is a programming language built around actors -- lightweight, isolated processes that communicate through messages. If you've ever wondered what safe concurrency looks like without locks, mutexes, or data races, Hew is your answer. Hew Playground puts the full language on your iPhone or iPad.
Write real programs in a proper code editor with syntax highlighting, auto-indent, brace matching, and a keyboard accessory bar for quick symbol access. The Hew compiler runs on-device via WebAssembly, so you get live error and warning underlines as you type -- no internet required. Long-press any identifier to see its type. When your code is ready, tap Run to execute it on the Hew server and see output instantly.
LEARN FROM SCRATCH OR DIVE DEEP
Whether you're new to programming or exploring actor-based concurrency for the first time, Hew Playground meets you where you are.
- 12 interactive tutorials guide you from Hello World through actors, state machines, closures, and async/await
- 13 built-in examples show real patterns: spawning actors, handling errors, matching enums, and more
- 19 quick reference cards explain every syntax construct, each with a "Try It" button that loads the snippet into the editor
- Full documentation from hew.sh is available in-app, with offline fallback
A REAL DEVELOPMENT ENVIRONMENT
- Context-aware autocomplete powered by the compiler
- Save, rename, and organise programs across sessions
- Import and export .hew files through the native file picker
- Share code as text, as a hew.run link, or via the system share sheet
- Cancel long-running programs with the Stop button
- Unsaved changes protection and auto-save when backgrounded
DESIGNED FOR EVERY DEVICE
Hew Playground is optimised for iPad with a side-by-side editor and output pane connected by a resizable divider. It supports Dynamic Type, VoiceOver labels on all controls, and full keyboard navigation. Available in 11 languages.
Hew is an actor-based programming language designed for safe, concurrent systems. Learn more at https://hew.sh
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Hew v0.5 compiler snapshot — the on-device WebAssembly engine now runs the v0.5 compiler, bringing updated diagnostics with precise source spans and phase-aware error messages.
Examples, tutorials, and quick reference updated — all code snippets now use Hew v0.5 explicit-width integer types (i64, u64, i32, …).
Semantic language services — the editor uses the v0.5 WASM language server for completion, rename, find references, signature help, and inlay hints.
Improved diagnostic experience — diagnostic spans are validated on decode; code actions are scoped to the selected diagnostic and can be applied directly in the editor.
The developer, Stephen Olesen, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Stephen Olesen
- Size
- 24 MB
- Category
- Developer Tools
- Compatibility
Requires iOS 26.0 or later.
- iPhone
Requires iOS 26.0 or later. - iPad
Requires iPadOS 26.0 or later. - Mac
Requires macOS 26.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 26.0 or later.
- iPhone
- Languages
English and 10 more
- English, French, German, Hindi, Japanese, Korean, Portuguese, Russian, Simplified Chinese, Spanish, Traditional Chinese
- Age Rating
4+
- 4+
- Copyright
- © Stephen Olesen