Write Rust in your browser. Editor is live today.
The Rust editor with syntax highlighting, rustfmt-style formatting, and code persistence is live now. Server-side compilation is provisioning — your borrow-checked solutions will be waiting when execution goes live at this same URL.
What works today
The Monaco editor with Rust syntax highlighting and rustfmt-style formatting is live now. The Run button shows a 'server execution provisioning' notice because compiling Rust requires the Rust compiler (rustc), which is not yet available in a browser WebAssembly execution environment for general programs.
We shipped the editor early for the same reason we did for Go, Java, and C++: writing, reading, and formatting code is independently useful. Candidates can compose their Rust solutions in a properly highlighted editor, review the borrow checker patterns, and paste them into a local environment or interview platform to run.
When compilation goes live, the URL is permanent and localStorage is preserved. You do not need to re-paste anything.
Rust edition and features in the editor
The editor understands Rust 2021 edition syntax: pattern matching with destructuring, async/await, const generics, GATs (generic associated types in stable Rust as of 1.65), let-else, let chains, and the full standard library module tree. If you are comfortable with modern Rust, the editor follows the same syntax.
Standard library autocompletion covers the collections that appear most in interview problems: Vec, HashMap, BTreeMap, HashSet, BTreeSet, VecDeque, BinaryHeap, and their common methods. The std::collections module is the primary reference for data structures, and the editor surfaces its API correctly.
The formatter applies rustfmt rules: 4-space indentation, line length of 100 by default, trailing commas in multi-line expressions, use keyword grouping. Interviewers who work in Rust recognize this style immediately.
Rust for interviews: the ownership advantage
Rust interviews are uncommon but growing, especially at systems software companies, infrastructure teams, and companies building performance-critical services in safety-first environments. Candidates who interview in Rust are usually expected to demonstrate comfort with ownership, borrowing, and lifetimes in their solutions.
The borrow checker is the most distinctive part of writing Rust for an interviewer. A solution that compiles in Rust has already been verified for memory safety — the interviewer knows the code cannot have a use-after-free or data race by construction. Explaining that to an interviewer while writing the solution is part of the expected narrative.
For algorithm problems, Rust solutions often involve pattern matching on enums (Option, Result), iterators (map, filter, flat_map, fold, collect), and explicit lifetime annotations for recursive data structures like linked lists and trees. The editor highlights all of these correctly and formats them according to community conventions.
When execution arrives
Rust compilation will use the stable channel of rustc (latest stable release at time of deployment) with the 2021 edition. Compile errors will be shown in the output panel with rustc's full diagnostic output, including the suggestions that rustc provides for common mistakes.
The execution environment will be sandboxed and have no network access. Standard input can be provided; stdout and stderr will appear in the output panel. Cargo features and external crates will not be available in the initial release — just the standard library. This matches how most Rust interviews are conducted.
Free, no account, no run limit — same as the Python and JavaScript runners today.
Frequently asked questions
- Can I run Rust code today?
- Not yet — the editor and formatter are live, but server-side compilation is provisioning. Python and JavaScript run instantly today. Rust execution will appear at this URL when it goes live.
- Which Rust edition will be supported?
- Rust 2021 edition, latest stable channel. The editor already understands 2021 edition syntax including let-else, const generics, and pattern matching improvements.
- Will Cargo and external crates work?
- The initial release will support std only, matching the constraints of most Rust interview environments. External crates may be added later.
- Can I save my Rust code now?
- Yes. The editor saves your code to localStorage automatically. Your solution will be waiting when execution goes live.
- Will compile errors be shown?
- Yes. When execution is live, rustc's full diagnostic output — including the 'help:' and 'note:' hints — will appear in the output panel. This is more informative than most online Rust compilers that truncate the error output.
- What is the catch?
- No catch. We give away the compiler to introduce candidates to our AI interview assistant. Use it forever for free.