About XpressDevTools

A fast, privacy-conscious, no-nonsense collection of utilities for developers — built for the everyday rhythm of writing code.

Why we built this

Every developer ends up searching for the same things: format some JSON, decode Base64, inspect a JWT, test a regex, generate a UUID, convert a timestamp, compare hashes, or quickly transform text.

XpressDevTools is different. Every tool here runs entirely in your browser. The server ships a Razor-rendered HTML page and a small JavaScript file, and from then on the tool works on your device — the content you paste, type, or generate is never uploaded and never logged. Close the tab and there is nothing left behind.

Two features step outside the browser by design, and we call them out plainly: the Feedback form sends the message you write (plus your IP, for spam protection) to our server, and the What's My IP tool asks our server which IP your request arrived on. Neither touches the data you put into any other tool. The details are in our Privacy Policy.

How it works

XpressDevTools is built as an ASP.NET Core application that delivers lightweight pages. Most tool functionality runs locally in your browser using JavaScript and browser APIs.

Close the tab and your processed content generally stays with you — not stored in an account, profile, or permanent database.

Built for real developer workflows

XpressDevTools is designed for the kinds of quick, repetitive tasks developers hit dozens of times a week, across a growing set of tool families:

  • JSON & data — format, validate, diff, and convert between JSON, YAML, CSV, and typed models;
  • Encoding & hashing — Base64, URL, HTML-entity encode/decode and MD5/SHA hashing;
  • Auth, certs & keys — JWT decoding, JWK↔PEM conversion, and TLS certificate inspection;
  • Generators & time — UUIDs, secure passwords, Unix-timestamp and timezone conversion, cron expressions, and lorem ipsum;
  • Text & code — regex testing, Markdown preview, SQL formatting, CSS/JS minifying, and LLM token counting;
  • Color & accessibility — color-format conversion and WCAG contrast checking;
  • Network — DNS and reverse-DNS lookups, What's My IP, and HAR file analysis.

New tools get added regularly — the full, current list is on the home page.

The XpressTools family

XpressDevTools is part of the XpressTools family of free, focused utilities, all linked from the hub at XpressTools.

Sister sites include XpressImgTools for browser-based image compression, resizing, cropping and format conversion, and XpressLogViewers for inspecting and filtering log files.

Why it stays free

A small, unobtrusive ad helps cover hosting and operating costs so the tools can remain free.

We avoid the usual friction:

  • No forced sign-ups;
  • No unnecessary upsells;
  • No interruptions inside tool workflows; and
  • No paywall for core functionality.

Suggest a tool

Missing something you'd like to see?

Hit the Feedback button in the top navigation and send us a note.

The bar is simple: useful, fast, and respectful of your data.