Free .NET developer tools
Tools for the jobs .NET developers do every day: turn JSON into C# classes, decode a JWT the way ASP.NET Core does, check a cron expression for Hangfire or Quartz.NET, and more.
- Free, no sign-up
- Nothing leaves your browser
- Tested against real .NET
Generate C# code
Paste data or a command, get C# that compiles.
JSON
Format, check, compare and query JSON, the way System.Text.Json and Newtonsoft read it.
JSON Formatter and Beautifier
Format, beautify or minify JSON exactly as System.Text.Json writes it.
JSON Validator
Validate JSON and get the exact System.Text.Json error, line and position.
JSON Diff
Compare two JSON documents and list every added, removed and changed value.
JSONPath Tester
Run JSONPath queries on JSON the way Newtonsoft's SelectTokens does.
JSON Escape
Escape text for a JSON string, and get it as a C# string literal.
JSON Unescape
Turn an escaped JSON string from a log back into readable JSON.
JSON to CSV Converter
Turn a JSON array into CSV, with the CsvHelper C# code.
CSV to JSON Converter
Turn CSV into a JSON array, with type detection and the C# code.
CSV Viewer
Open a CSV as a sortable, filterable table, right in your browser.
XML and YAML
XML and YAML tools with the same output and errors as .NET.
XML Formatter and Beautifier
Format or minify XML with the same output as .NET's XmlWriter.
XML Validator with XSD
Validate XML against an XSD with the same errors as .NET's XmlReader.
XPath Tester
Run XPath on XML and see the matching nodes, as XPathNavigator finds them.
XML to JSON Converter
Convert XML to JSON the way Newtonsoft's SerializeXmlNode does.
JSON to XML Converter
Convert JSON to XML the way Newtonsoft's DeserializeXmlNode does.
JSON to YAML Converter
Convert JSON to YAML and back, with clear errors.
YAML to JSON Converter
Convert YAML to JSON the way YamlDotNet reads it, types included.
YAML Formatter
Re-indent YAML and keep comments, the way YamlDotNet's Emitter writes it.
YAML Validator
Check YAML syntax and get the exact YamlDotNet error, line and column.
Dates and time
Timestamps, time zones and schedules, matched against how .NET parses them.
Unix Timestamp and .NET Ticks Converter
Convert epoch seconds, milliseconds, ticks, FILETIME and OADate to dates.
Windows and IANA Time Zone Converter
Map time zone IDs the way TimeZoneInfo does, and convert times between zones.
Cron Expression Builder for .NET
Check a schedule for Hangfire, Quartz.NET or Azure Functions, with the next runs.
C# DateTime Format Tester
Try any DateTime format string in 45 cultures and see the exact output.
Text and numbers
Patterns, formats, number bases and text, run by the real .NET rules.
.NET Regex Tester
Test C# regular expressions with the real .NET engine in your browser.
C# Number and String Format Tester
Check N2, C, P, custom formats and interpolation for int, double and decimal.
Case Converter
PascalCase, camelCase, snake_case and more, with .NET naming rules.
Diff Checker
Compare two texts side by side with the changed words highlighted.
SQL Formatter
Format T-SQL and other SQL, checked with the SQL Server parser.
Text to Binary (Binary Translator)
Turn text into binary and back, byte by byte, in any encoding.
Hex to Decimal Converter
Convert hex to decimal, with two's complement and C# literals.
Decimal to Hex Converter
Convert decimal to hex, negatives included, with ToString("X").
Binary to Decimal Converter
Read binary as signed or unsigned numbers, with C# 0b literals.
Random String Generator
Secure random strings, passwords and tokens, with RandomNumberGenerator code.
Encoding
Bytes, escapes and hidden characters, with the matching .NET code.
BOM Checker and Remover
Find and strip the hidden byte order mark that breaks JSON, CSV and scripts.
Hex to String Converter
Convert text to hex and hex back to text, in any encoding.
HTML Encode and Decode
Escape and unescape HTML entities, and see WebUtility vs HttpUtility.
Base64 Encode and Decode
Encode or decode Base64 and Base64Url text and files.
URL Encode and Decode
Percent-encode text and see Uri.EscapeDataString vs UrlEncode.
Unicode Converter
See code points, UTF-8 and UTF-16 bytes and C# escapes for any text.
Security and hashing
Tokens, hashes and passwords. Your keys never leave the page.
JWT Decoder for ASP.NET Core
Decode a token and see how AddJwtBearer validates it, including 401 causes.
JWT Generator
Create signed test JWTs that pass AddJwtBearer, with the matching settings.
HMAC Generator
Create HMAC-SHA256, SHA-1 and SHA-512 signatures and verify webhooks.
SHA-256 Hash Generator
Hash text or files with SHA-256, with the C# code to match.
SHA-1 Hash Generator
Hash text or files with SHA-1, and see why it is no longer safe for signing.
MD5 Hash Generator
Get an MD5 checksum for text or files. Not for passwords.
PBKDF2 Generator
Derive password hashes with PBKDF2, the way Rfc2898DeriveBytes does.
bcrypt Generator
Hash and verify passwords with bcrypt at any cost factor.
ASP.NET Core Identity Hash Decoder
Read the format, iterations and salt inside an Identity password hash.
Configuration and IDs
Settings, connection strings and IDs that work the first time.
appsettings.json to Environment Variables
Convert settings to Docker, Kubernetes, Azure and GitHub Actions variables, and back.
Connection String Builder
Build and check connection strings for SQL Server, PostgreSQL, MySQL, SQLite and more.
GUID / UUID Generator
Generate v4, v5 and v7 GUIDs, decode them, and check SQL Server sort order.
ULID Generator
Generate and decode ULIDs, and convert them to and from GUIDs.
Snowflake ID Generator
Generate and decode Snowflake IDs, with the IdGen C# code.
Debugging and reference
Errors, status codes, versions and cheat sheets, explained for .NET.
HTTP Status Codes in ASP.NET Core
Every status code, what it means, and how ASP.NET Core returns it.
Stack Trace Cleaner
Paste an exception, get a readable stack trace with the frames that matter.
.NET Versions and Support Dates
Release and end-of-support dates for every .NET and .NET Framework version.
SQL Server to C# Types
Every SQL Server type with its C#, SqlDbType and EF Core mapping.
.NET Regex Cheat Sheet
The .NET regex syntax on one page, every example run against .NET.
C# Cheat Sheet
Modern C# on one page: records, patterns, LINQ, async. Every snippet compiles.
.gitignore for .NET
The Visual Studio .gitignore, explained section by section, ready to download.
Questions
Are these tools free?
Yes. Every tool is free and needs no account.
Does my data leave the browser?
No. Every tool runs in your browser. Tokens, keys, connection strings and files you paste are not sent anywhere.
Why tools made for .NET?
Generic tools often give answers .NET does not. Each tool here follows what the .NET libraries actually do, and is tested against the real libraries.
Go further than the tools
Code Maze courses take you from these everyday jobs to building complete ASP.NET Core applications.