Minify JSON in C#

JSON minification removes insignificant whitespace while preserving the represented data. A parser-based approach is safer than regular expressions because whitespace inside strings must be preserved.

Quick Start#

The following example uses the standard C# API or a widely used package for this task.

Quick start#

1using System.Text.Json;23using JsonDocument doc = JsonDocument.Parse(input);4string minified = JsonSerializer.Serialize(doc.RootElement);5Console.WriteLine(minified);

Common Operations#

This second pattern covers a common production operation or a safer way to handle real input.

Write compact UTF-8 JSON#

1using var stream = File.Create("minified.json");2using var writer = new Utf8JsonWriter(stream, new JsonWriterOptions { Indented = false });3doc.RootElement.WriteTo(writer);4await writer.FlushAsync();

Important Notes#

Parsing before writing ensures that only syntactically valid JSON is emitted.

Best Practices#

1. Treat external input as untrusted and handle parse/validation errors explicitly.
2. Keep encoding, units, formats, and library-specific mapping rules explicit at system boundaries.
3. Add test vectors that cover empty input, Unicode text, malformed input, and representative production data.

References#

• RFC 8259: The JSON Data Interchange Format
• .NET API Browser