Developer tools built by a .NET engineer — including utilities you won't find anywhere else.

I'm Pankaj Kumar, a Senior Software Engineer who's been writing production C# since 2022 — most of my day is spent in ASP.NET Core, Blazor, and Entity Framework Core. I built DevToolsHub because the tools I kept reaching for were slow, cluttered, or asked me to paste sensitive data into sites I had no visibility into. The .NET-specific tools below — EF Core migration analysis, LINQ-to-SQL translation, appsettings diffing — exist because I needed them myself and couldn't find them anywhere else.

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.NET-specific tools

Built from real day-to-day .NET work — the kind of tool you end up writing yourself if nobody else has, because generic converters don't cover it.

.NET Tools

appsettings.json Environment Diff

Diffs appsettings.Development.json against Production to catch the exact config-key mismatch that breaks logins after deploy.

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.NET Tools

Connection String Builder & Validator

Builds or validates SQL Server, PostgreSQL, MySQL, and Cosmos DB connection strings — flags a missing Encrypt=True or a plaintext password before it ships.

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.NET Tools

SQL Table to C# Entity Generator

Turns a CREATE TABLE script into a ready-to-use EF Core entity, with your choice of data annotations or Fluent API configuration.

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.NET Tools

JSON to C# Class/Record Generator

Generates strongly-typed C# classes or records straight from a JSON payload — nested objects and arrays included.

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.NET Tools

XML to C# Class Generator

Generates XmlSerializer-decorated C# classes from any XML — handles attributes, collections, and nested types.

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.NET Tools

LINQ to SQL Converter

Shows you the actual SQL Server or PostgreSQL your LINQ query would generate, before you find out the hard way in production.

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.NET Tools

Csproj Analyzer & Cleaner

Finds the duplicate PackageReferences and redundant SDK-default properties quietly bloating your .csproj.

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.NET Tools

EF Core Migration SQL Explainer

Reads a dotnet ef migrations script and flags every DROP COLUMN and DROP TABLE before you run it against a real database.

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.NET Tools

C# to JSON Sample Generator

Generates a realistic sample JSON payload straight from a C# class or record — no more hand-typing test fixtures.

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.NET Tools

ASP.NET Core Route Tester

Tests ASP.NET Core route templates and constraints against a real URL, showing exactly why a route did or didn't match.

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NuGet Package Version Conflict Explainer

Paste NU1605/NU1107 error output and get the conflict chain explained with resolution snippets.

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.NET Tools

Dockerfile Generator for .NET

Generates a production-ready Dockerfile for ASP.NET Core apps with multi-stage build and non-root user by default.

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.NET Tools

Minimal API Endpoint Scaffolder

Scaffolds complete Minimal API endpoint groups with TypedResults, DTOs, and validation stubs from your entity fields.

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.NET Tools

C# ↔ VB.NET Converter

Converts between C# and VB.NET using Roslyn — handles records, pattern matching, async/await, and flags what needs manual review.

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.NET Tools

DateTime Ticks ↔ Date Converter

Converts a raw .NET Ticks value to UTC, local time, and Unix time — or back — without you doing the epoch math by hand.

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.NET Tools

.NET Stack Trace Formatter

Re-expands a collapsed or JSON-escaped stack trace into readable frames, with your own code visually separated from framework noise.

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appsettings.json ↔ Environment Variables Converter

Flattens appsettings.json into the exact double-underscore environment variables ASP.NET Core reads — ready for Docker or Azure App Service.

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web.config XDT Transform Tester

Tests a web.config XDT transform against your base config and shows exactly what changed, before a bad locator silently does nothing in production.

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C# String Escaper

Shows a string as all five C# literal forms at once — regular, verbatim, raw, and interpolated — so you stop guessing which one avoids the escaping mess.

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GUID Generator with C# Snippets

Generates GUIDs in any .NET format specifier with the matching C# and SQL Server snippets already written for you.

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From the blog

Practical guides on the formats and tools every developer works with.

14 Jul 2026 · 7 min read

Catastrophic Regex Backtracking in .NET: Timeouts and Safer Patterns

How nested quantifiers like (a+)+ cause exponential regex time in .NET, measured on .NET 8, with fixes: match timeouts, NonBacktracking, safer patterns.

03 Jul 2026 · 6 min read

Base64 vs Base64URL in .NET: When + and / Break URLs

Base64 can contain + and /, which behave differently in URL paths and query strings. Tested ASP.NET Core examples and the Base64URL fix.

30 Jun 2026 · 6 min read

JWT Clock Skew in .NET: Fixing IDX10222 (Token Not Yet Valid)

Why a valid JWT is rejected as not yet valid when clocks differ, how ClockSkew works (default 5 minutes), and how to backdate nbf. Tested on .NET 8.

01 Jun 2026 · 7 min read

DateTime vs DateTimeOffset in .NET: Comparison Pitfalls

DateTime comparison ignores Kind, so Local, Utc and Unspecified compare by ticks. Tested examples, the Unix-timestamp trap, and the DateTimeOffset fix.

View all articles →

All tools

48 more tools, grouped by category. Every link below is a real page — expand a category or use the search box in the sidebar.

Formatters (7)
JWT & Auth (4)
Encoding & Hashing (5)
Generators (7)
Converters (13)
Text & Analysis (6)
Web & Dev (6)

About DevToolsHub

DevToolsHub is a free collection of browser-based developer utilities built for developers who want fast, no-fuss tools without signing up, installing software, or pasting sensitive data into unknown third-party services. Every tool on the site processes your input one of three ways: entirely in your browser, in-memory on the server for the duration of your active session, or via a dedicated API over HTTPS that returns the result and discards the input. Inputs are not written to a database or log; the Privacy Policy covers the short-lived result cache and monitoring data.

The site covers the tools developers reach for dozens of times a week: formatters for JSON, SQL, YAML, HTML, CSS, and XML; encoders and decoders for Base64, URLs, and HTML entities; generators for UUIDs, passwords, QR codes, cron expressions, and .gitignore files; converters for timestamps, timezones, number bases, CSV/JSON, JSON/YAML, and text case; date difference calculators; CSS gradient generators; and testing tools for regex patterns, text diffs, and JWT tokens. New tools are added regularly based on feedback from the developer community.

DevToolsHub is built with ASP.NET Core 8, Blazor Server, and MudBlazor, and hosted on Microsoft Azure. The site is designed to load fast, work on any screen size, and stay out of your way — no mandatory sign-ups, no upsell prompts, no dark patterns. The blog has a small set of tested guides on .NET topics the tools relate to: JWT clock skew, regex backtracking, DateTime vs DateTimeOffset, and Base64 vs Base64URL.

DevToolsHub was built and is maintained by Pankaj Kumar, a software developer based in India. If you find a bug, want to request a tool, or have feedback, use the contact page or email [email protected].

Why DevToolsHub?

  • No login or account required for any tool
  • Inputs are not saved — they are processed in memory and discarded
  • All 68 tools in one place, no switching between sites
  • Works on desktop, tablet, and mobile
  • Dark and light mode with accent colour choices
  • Completely free, no premium tier
  • New tools added based on community requests