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About Online Swift Formatter

Writing Swift that **compiles** is easy. Writing Swift that’s **beautiful, consistent and review-ready** is harder. This online Swift Formatter uses SwiftFormat-style rules to normalize indentation, spacing and line wrapping so your `.swift` files stay clean across Xcode, Swift Playgrounds and CI pipelines.

Key Features of the Swift Formatter

  • **One-click cleanup** of indentation, spacing and braces in Swift code
  • **Configurable indent size** via the *Indent Size* slider (1–8 spaces)
  • **Wrap / Line Length** control to keep long expressions within your preferred column width
  • Supports standard `.swift` source files and pasted snippets
  • Great for **iOS, macOS, watchOS, tvOS and server-side Swift** projects
  • Uses a SwiftFormat-style engine behind the scenes for idiomatic Swift output
  • Idempotent formatting – running it multiple times keeps the same output
  • No account required – just paste, format and copy the cleaned result

🛠️ How to Use the Swift Formatter for swift-formatter

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1. Paste or Upload Your Swift Code

📥 Paste Swift code directly into the editor, or drag-and-drop a `.swift` file. The tool is optimized for typical Xcode-style Swift sources.

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2. Set Indentation & Line Length

📏 Use the **Indent Size** slider to choose how many spaces each indentation level should use, and configure **Wrap / Line Length** to control where long lines should be wrapped (or set it to `0` to disable wrap-based formatting).

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3. Click “Format”

⚡ Press the **Format** button to apply SwiftFormat-style rules. The formatter normalizes indentation, spaces around `:` and operators, and wraps long lines according to your settings.

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4. Review and Copy the Result

🔍 Compare the original and formatted versions. When you’re happy with the result, copy the formatted Swift back into Xcode, a Swift Playground, or your Git commit.

Technical Specifications

Formatting Engine & Style

The tool mirrors common SwiftFormat conventions to keep your codebase consistent across files and contributors.

AspectBehaviorNotes
LanguageSwiftWorks best with Swift 5+ source files.
IndentationConfigurable spaces per levelControlled by the **Indent Size** option (1–8).
Line WrappingOptional wrap columnControlled by **Wrap / Line Length** (0–120; `0` = no wrap).
WhitespaceNormalized around `:` and operatorsImproves readability and consistency across code reviews.
Idempotent OutputSame input → same outputSafe to run multiple times without drifting formatting.

Supported Input & Limits

Focuses on real-world Swift source files used in Apple platform and server-side Swift projects.

ParameterValue / BehaviorNotes
File extensions.swiftStandard Swift source files.
MIME typestext/x-swiftUsed internally for editor and dropzone detection.
Max input size≈ 2 MB of sourceVery large files are better formatted via local SwiftFormat in CI.
Output extension.swiftFormatted content is best saved as a Swift source file.

Validation & Errors

The formatter expects syntactically valid Swift. If the input is incomplete or contains major syntax errors, it may fail or return an error message instead of formatted output.

Command Line Alternatives with SwiftFormat

Want the same style in Xcode, CI or pre-commit hooks? Use SwiftFormat directly:

macOS (Homebrew)

Install SwiftFormat via Homebrew

brew install swiftformat

Adds the `swiftformat` CLI to your system.

Format a single Swift file

swiftformat MyViewController.swift

Rewrites the file in place using default SwiftFormat rules.

Format an entire Xcode project

swiftformat .

Recursively formats all `.swift` files in the current directory.

Project-level Configuration

Use a custom configuration

swiftformat . --config .swiftformat

Apply team-specific rules stored in a `.swiftformat` config file.

Integrate with Git pre-commit

swiftformat . && git commit

Run SwiftFormat before each commit to keep your main branch clean.

Use this online tool for quick one-off cleanups, then mirror the same style in your repo using SwiftFormat and a shared `.swiftformat` file.

Practical Use Cases for the Swift Formatter

iOS & macOS App Development

Keep UIKit, SwiftUI and Combine-heavy code readable and consistent across feature branches.

  • Standardize formatting of view controllers, view models and services before code review.
  • Clean up scratchpad or prototype Swift code before copying it into production targets.
  • Align indentation and wrapping of complex SwiftUI view hierarchies.
struct ContentView: View {
  var body: some View {
    VStack {
      Text("Hello")
      Button("Tap me") {
        print("Tapped")
      }
    }
  }
}

Server-Side Swift (Vapor, Hummingbird, etc.)

Make API handlers and routing code easier to scan and review.

  • Reformat routes and middleware declarations so complex chains are easy to follow.
  • Clean up JSON encoding/decoding structs with long property lists.
  • Ensure consistent wrapping of long SQL or HTTP client calls inside Swift code.
app.get("hello") { req async throws -> String in
    "Hello, world!"
}

Teaching & Learning Swift

Show students what idiomatic Swift looks like and reduce “style noise” in exercises.

  • Normalize Swift code before sharing examples in slides or documentation.
  • Clean student submissions to focus on logic instead of spacing and indentation.
  • Demonstrate how good formatting improves readability without changing behavior.
func fibonacci(_ n: Int) -> Int {
    if n < 2 { return n }
    return fibonacci(n - 1) + fibonacci(n - 2)
}

❓ Frequently Asked Questions

❓What does this Swift Formatter actually change?

The formatter adjusts **indentation, spaces and line wrapping** to follow Swift-style conventions. It does not intentionally change the logic of your code – only how it is laid out.

📏What should I choose for Wrap / Line Length?

Common choices range from **80 to 100 characters**, depending on your team and display width. Use a smaller value for narrow layouts (like split-view Xcode) and a larger value if your team is comfortable with wider lines. Set it to `0` if you don’t want line-length-based wrapping.

🧹Is this a replacement for SwiftLint?

No. A formatter focuses on **layout and style** (indentation, wrapping, spacing), while SwiftLint focuses on **linting rules and potential issues** (unused code, naming, complexity). Many teams use both together.

🔒Is it safe to paste production Swift code here?

As a rule of thumb, avoid pasting highly sensitive code (like proprietary algorithms or secrets) into any online tool. For confidential projects, prefer running SwiftFormat locally or inside your CI system with a private configuration.

⚡Can I run this formatter automatically on every commit?

Yes – use **SwiftFormat** in your repository (for example via a Git pre-commit hook, Xcode Build Phase or CI job) to enforce the same style automatically. This online tool is ideal for quick checks and small snippets.

Pro Tips

Best Practice

Agree on a single **Indent Size** and **Wrap / Line Length** with your team, then mirror those values both in this tool and in your `.swiftformat` configuration.

Best Practice

Run the formatter on pull requests to keep code reviews focused on logic and architecture instead of spacing debates.

Best Practice

Use the formatter on generated Swift code (e.g. from codegen tools) so it looks as clean as your hand-written code.

Best Practice

Combine this formatter with Xcode’s “Re-Indent” only for quick local tweaks; use SwiftFormat in CI to maintain a truly consistent style.

Additional Resources

SwiftFormat (GitHub)
Documentation
Swift.org API Design Guidelines
Reference
Swift Language Guide
Documentation

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