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About the Objective-C Formatter Objective-C Code Formatter

Still working on an Objective-C codebase for iOS or macOS? This formatter runs your code through clang-format on a secured backend and returns polished .m / .mm output with consistent indentation, spacing and braces. Ideal for cleaning up legacy files, stabilizing diffs and enforcing a team-wide style without touching your local toolchain.

Key Features

  • Format Objective-C and Objective-C++ source files (`.m`, `.mm`) with a single click
  • Backed by LLVM’s clang-format for predictable, industry-standard formatting
  • Normalizes spaces around operators, method signatures, and message sends
  • Enforces consistent brace style for interfaces, implementations, and control-flow
  • Keeps imports clean and grouped for more readable headers and sources
  • Great for legacy Objective-C projects, mixed Swift/ObjC apps, and quick pre-PR cleanups
  • Server-backed execution with timeouts and size limits to keep the UI responsive

🛠️ How to Format Objective-C Code for objectivec-formatter

1

1. Paste or upload your code

Paste your Objective-C / Objective-C++ source into the editor or drag-and-drop a `.m` / `.mm` file. You can also paste header snippets to clean them up quickly.

2

2. Run the formatter

Hit the **Format** button. Your code is sent to a secured endpoint where clang-format runs with an Objective-C style profile. The formatted result is returned in seconds.

3

3. Review, copy, and commit

Inspect the output, then copy it back into Xcode or your editor. Commit the clean file to keep your diffs focused on logic instead of whitespace.

Technical Specifications

Supported Inputs

Built for everyday Objective-C / Objective-C++ development.

TypeExamplesNotes
.m source filesView controllers, models, managersFully supported for upload and paste.
.mm Objective-C++ filesBridging C++ with Cocoa APIsFormatted using clang-format’s Objective-C++ support.
Header snippets@interface blocks, protocols, categoriesPaste header code directly into the editor for cleanup (file upload expects `.m` / `.mm`).

Formatter Engine

The formatter delegates to clang-format on a secured backend.

AspectDetail
EngineLLVM clang-format (Objective-C / Objective-C++)
Execution modelServer-backed via a dedicated `/api/objectivec-formatter` endpoint
Timeout~25 s safety timeout per request
Reformat scopeWhitespace, indentation, braces, some import layout
SemanticsCode behavior is not changed—only layout is adjusted
For highly sensitive or proprietary codebases, prefer running clang-format locally in your CI or on your own machine rather than any online tool.

Style & Layout

Code is printed using a stable clang-format style profile.

CategoryWhat is normalized?Why it matters
Method signaturesSpacing around `-`, return types, parameters and pointersMakes method declarations easy to scan in headers and implementations.
Message sendsSpaces after commas, around colons, and in nested callsImproves readability of deeply nested `-[obj doSomething:withOption:]` calls.
Braces & control-flowBrace placement for `@interface`, `@implementation`, `if`, `for`, `while`Prevents style drift across files and contributors.
ImportsGrouping and spacing for `#import` and `#include`Keeps top-of-file sections tidy and reduces merge conflicts.
Indentation & alignmentUniform indentation for blocks, switches, and nested scopesEliminates misaligned blocks from quick manual edits.

Limits & Performance

Sized for real-world Objective-C apps and libraries without freezing your browser.

Input TypeApproximate LimitNotes
Pasted source~2 MB of textHard limit enforced before sending to the backend.
Uploaded file~5 MBBounded by the tool’s configured `maxFileSizeBytes`.
Typical latency< 1–2 sDepends on file size, network latency and server load.
Failure modesTimeout / error messageErrors are surfaced cleanly instead of hanging the UI.

Privacy Model

Server-backed, transient processing for formatting only.

AspectBehavior
TransportCode is sent via HTTPS to a secured formatting endpoint.
StorageIntended as transient: input is processed in-memory and not stored long-term.
SecretsYou should avoid pasting API keys, tokens, or production credentials into any online tool.
Best practiceUse this tool for non-sensitive files and quick cleanups; keep CI and critical formatting inside your own infrastructure.

Command-Line clang-format for Objective-C

For day-to-day development and CI, clang-format in your local toolchain is the canonical way to keep Objective-C code consistent.

macOS / 🐧 Linux

Format a single `.m` file in place

clang-format -i MyViewController.m

Rewrites the file on disk using the configured style (e.g., from `.clang-format`).

Preview formatted output without changing the file

clang-format MyViewController.m

Prints formatted code to stdout so you can review the diff first.

Format all Objective-C sources in a project

find . -name "*.m" -o -name "*.mm" | xargs clang-format -i

Applies consistent formatting across your entire Objective-C / Objective-C++ codebase.

Windows

Format a header or implementation file

clang-format.exe -i MyClass.h

Updates the header in place with your chosen clang-format style.

Run as part of a script

forfiles /S /M *.m /C "cmd /c clang-format.exe -i @file"

Simple batch formatting for Objective-C sources in a repository.

Store your team’s style in a `.clang-format` file at the root of your repo, then use this web tool for quick one-off fixes and local clang-format for automated, repo-wide consistency.

Practical Use Cases

iOS / macOS App Development

Keep long-lived Objective-C apps maintainable alongside newer Swift modules.

  • Clean up legacy view controllers and model objects before major refactors.
  • Apply consistent style across a mixed team of senior and junior Objective-C developers.
  • Run formatting before commits to reduce noisy diffs in pull requests.
@interface MyViewController : UIViewController
@property(nonatomic, strong) NSString *titleText;
@end

@implementation MyViewController
- (void)viewDidLoad {
[super viewDidLoad];NSLog(@"Loaded: %@",_titleText);}
@end

Code Review & Pull Request Prep

Use formatting as a pre-flight step to keep review discussions focused on logic.

  • Run the formatter on changed files before opening a PR to eliminate whitespace noise.
  • Make diffs smaller and easier to review by stabilizing brace style and indentation.
  • Reduce style debates by delegating to a single clang-format profile.
// Before review: inconsistent spacing
if(showAlert){[self showAlertWithMessage:message];}

// After formatting
if (showAlert) {
  [self showAlertWithMessage:message];
}

❓ Frequently Asked Questions

🛠️What formatter engine is used under the hood?

The tool uses LLVM’s `clang-format`, the standard formatter for C, C++, Objective-C, Objective-C++ and related languages. Your code is parsed and reprinted according to a stable Objective-C style profile.

📄Which file types are supported?

The uploader is optimized for `.m` and `.mm` implementation files. You can still paste header contents (`.h`) directly into the editor to clean them up, but file uploads are focused on `.m` / `.mm` for now.

📏Can I control indentation or max line width from the UI?

The web interface runs clang-format with a predefined Objective-C style profile. If you need fine-grained control over options like `IndentWidth` or `ColumnLimit`, use a `.clang-format` file and run clang-format locally in your project or CI.

🔐Is my source code stored or logged?

Code is sent via HTTPS to a secured formatting endpoint and processed as transient input. It is not intended to be stored long-term. Still, as a best practice, avoid including secrets, credentials, or highly sensitive business logic in any online tool.

⚠️Can formatting ever change how my code behaves?

clang-format focuses on whitespace and layout and should not change semantics. However, if your code relies on unusual macro tricks or formatting-sensitive tooling, always run the formatter on a separate branch or backup and rely on tests to confirm behavior is unchanged.

🚀When should I use this web tool vs local clang-format?

Use this web formatter for quick cleanups, one-off files, or when you’re on a machine without clang-format installed. For full projects, automated workflows, and style enforcement, keep clang-format in your editor and CI with a shared `.clang-format` configuration.

Pro Tips

Best Practice

Run the formatter before committing to keep pull request diffs focused on behavior instead of brace placement.

CI Tip

Add a `clang-format` step to your CI (or a pre-commit hook) so that style issues never reach code review.

Best Practice

Keep imports sorted and grouped; it reduces merge conflicts when several teammates touch the same files.

Security Tip

Avoid pasting production secrets or tokens into any online formatter. For sensitive code, run clang-format locally inside your own infrastructure.

Additional Resources

Clang-Format Style Options
Documentation
Apple Developer Docs: Objective-C
Documentation
Objective-C Style Guide (NYTimes)
Documentation

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