Free Offline Developer Tools
Fast, private, browser-based utilities for hashing, formatting, and generating data — no installs, no servers, no data ever leaves your device.
category Categories
Generators
Generate hashes, identifiers, and random strings instantly.
Network & Infrastructure
Subnet math, connectivity checks, and DNS lookups for networking and sysadmin work.
apps Tools
MD5 Generator
Generators
Generate an MD5 hash from any text directly in your browser.
JSON Formatter
Formatters
Format, validate, and beautify JSON data in one click.
UUID Generator
Generators
Create standards-compliant UUIDs for your apps and databases.
Text Diff
Text
Compare two blocks of text and highlight every difference.
Base64 Encoder / Decoder
Converters
Encode or decode Base64 text with no server round-trip.
SHA-1 Generator
Generators
Generate a SHA-1 hash from any text directly in your browser.
Random String Generator
Generators
Create secure random strings and passwords with custom rules.
Length Counter
Text
Count characters, words, and lines in your text instantly.
IPv4 / IPv6 Subnet Calculator
Network & Infrastructure
Calculate subnet masks, broadcast addresses, and usable IP ranges offline.
Client IP & WebRTC Leak Test
Network & Infrastructure
See the public and local (LAN) IP addresses your browser exposes.
DNS-over-HTTPS (DoH) Lookup
Network & Infrastructure
Look up A, AAAA, MX, and TXT records over a public DoH endpoint (requires internet).
QR Code Generator
Generators
Create a custom QR code with your own colors, a logo, and a caption.
QR Code Reader
Converters
Scan a QR code with your camera or decode one from an image file.
URL Encoder / Decoder
Converters
Encode special characters and parameters safely, or decode them back.
HTML Viewer & Live Preview
Formatters
Render raw HTML and code instantly in a secure, isolated sandbox.
SQL Formatter
Formatters
Beautify raw SQL queries, or compact them back down, in one click.
XML Formatter
Formatters
Make unstructured XML files readable with proper indentation.
Regex Tester
Text
Test and highlight regular expressions against your text in real time.
URL Parser
Network & Infrastructure
Break a complex URL into its parts — protocol, host, port, path, query, hash.
IP Lookup
Network & Infrastructure
See your public IP address with its country, city, ISP and ASN, or look up any IP.
Why MikroBI DevKit is different
MikroBI DevKit bundles a growing collection of everyday developer utilities — hash generators, a JSON formatter, a Base64 encoder, a UUID generator, and more — into a single toolbox that runs entirely inside your browser tab. There's no backend to sign up for, no API key to request, and no rate limit to hit: every calculation, from computing a hash to reformatting a JSON payload, happens on the same machine you're already working on. That local-first design isn't just a convenience; it's the foundation the rest of the toolbox is built on, shaping how data is handled, how the app behaves without a network connection, and how tools can be chained together into small workflows.
Every tool that touches sensitive input — hashing, encoding, random generation — relies on the Web Crypto API and other native browser primitives rather than a server-side script. When you generate an MD5 or SHA-1 digest, or ask for a cryptographically random string, the computation runs inside the JavaScript engine of your own browser using APIs built directly into the platform. Nothing you type is transmitted over the network, logged in a database, or visible to any third party, because there is no server in the request path to send it to. This client-side model matters most for anything you'd rather not paste into a random web form: internal identifiers, draft configuration, or text you're just not sure is safe to upload. Closing the tab clears the working state completely, and reloading the page starts from a blank slate — there's no hidden history of what you've processed.
MikroBI DevKit is built as a Progressive Web App, which means the entire toolbox — its interface, its logic, and every tool it ships — is downloaded once and cached by a service worker running in the background. After that first visit, the app keeps working even if your connection drops, whether that's a spotty train Wi-Fi, an airplane with no signal, or an internal network with no outbound internet access at all. You can also install it to your home screen or desktop like a native app, launching it in its own window without a browser address bar. Because the tools don't depend on a live connection to function, the offline-first architecture isn't just a resilience feature — it reinforces the privacy story above: if a tool can run with no network at all, you can be confident it isn't quietly sending your data anywhere while you use it.
Real developer work rarely stops at a single transformation. You might need to generate a random string, hash it, and then check its length, or format a JSON blob and diff it against another version. To support that, every tool output includes a "Send to…" action that hands its result directly to another tool in the toolbox, pre-filling the next tool's input without any manual copying or retyping. That pipeline turns a set of otherwise isolated utilities into a lightweight workflow builder: chain a generator into a formatter, a formatter into a diff tool, or a converter into a hash generator, and move through multi-step tasks in a few clicks instead of juggling clipboard contents between browser tabs.
Taken together, browser-native cryptography, offline-first caching, and an inter-tool pipeline are what separate MikroBI DevKit from a loose collection of single-purpose web forms. Each tool is small and focused on its own, but the underlying architecture — privacy by default, resilience without a connection, and the ability to connect tools into a chain — is what makes the toolbox useful for repeated, everyday work rather than a one-off lookup. As new tools are added, they inherit the same guarantees: local execution, offline availability, and a pipeline-ready output, so the toolbox grows without asking you to trust it any less.