No sign-up required · runs entirely in your browser

Small tools that stay out of the way

Northwind DevKit is a compact set of everyday utilities for people who work with JSON, text encodings, timestamps, regular expressions and language-model prompts. Nothing is uploaded — every conversion happens on your own machine.

Browse the tools Try the JSON formatter

Works offline · No accounts · No tracking scripts

The toolkit

Five utilities, one consistent workflow

Each tool shares the same layout, keyboard shortcuts and copy behaviour, so moving between them takes no relearning.

JSON Formatter & Validator

Pretty-print or minify JSON, switch between 2-space, 4-space and tab indents, and get a precise line/column report when parsing fails.

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Base64 Encode & Decode

Convert text to and from Base64 with full UTF-8 support, so emoji and non-Latin scripts survive the round trip intact.

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Unix Timestamp Converter

Translate epoch seconds or milliseconds into local, UTC and ISO 8601 time — and back again — with a live clock for reference.

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Regex Tester

Build and debug regular expressions against sample text, with live match highlighting, capture-group tables and flag toggles.

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Token Counter

Estimate how many tokens a passage will use across common model families, with character, word and byte counts alongside.

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More on the way

URL parsing, hash generation and diff viewing are in progress. The whole toolkit is built as plain HTML, CSS and JavaScript, so new tools ship quickly.

In development
Why DevKit

Built for the ten-second task

Most developer utilities are heavier than the problem they solve. DevKit optimises for speed, predictability and getting out of your way.

  • Processed locally

    Input is parsed in the browser tab. Nothing is transmitted, logged or stored on a server.

  • Loads in one request

    No font downloads, no analytics, no third-party scripts. The pages stay usable on a flaky connection.

  • Readable error messages

    When input is malformed you get a position and an explanation, not a silent failure or a blank panel.

  • Keyboard first

    Copy and run shortcuts, sensible tab order and visible focus rings throughout every tool.

  • Light and dark

    A theme toggle that respects your operating-system setting and remembers what you picked.

  • No account wall

    Every tool is open to anyone. Paid plans exist for teams that want history, presets and shared snippets.

Pricing

Free for individuals, simple for teams

The browser tools are free and stay free. Paid tiers add saved workspaces, history and shared configuration.

Free

For anyone who needs a quick conversion.

$0 / forever

Start using the tools
  • All five browser tools
  • Unlimited use, no sign-up
  • Light & dark themes
  • Offline capable
Most popular

Pro

For developers who live in these tools.

$6 / month

See what's included
  • Everything in Free
  • Saved snippets & presets
  • Recent-input history
  • Custom regex flag sets
  • Email support

Team

For groups standardising their workflow.

$18 / month

Talk to us
  • Everything in Pro
  • Shared team library
  • Self-host package
  • Central configuration
  • Priority support
FAQ

Questions we get asked

Is my data uploaded anywhere?

No. Each tool is a self-contained page that runs in your browser. The text you paste is parsed in the tab, and nothing is sent to a server, written to a cookie, or included in a request log.

Do the tools need an internet connection?

Once a page has loaded it keeps working if your connection drops. There are no CDN dependencies, web fonts or background requests, so a slow or restricted network does not degrade the tools.

How accurate is the token counter?

It is an estimate. Different model families use different tokenisers, and the counter uses a documented heuristic rather than shipping every vocabulary. Treat the output as a planning figure, not a billing figure.

Which browsers are supported?

Current versions of Chrome, Edge, Firefox and Safari, on desktop and mobile. The pages use standard HTML, CSS and JavaScript, and no feature that would break on an older evergreen browser.

Can we host DevKit inside our own network?

Yes. The Team plan includes a self-host package: copy the static files behind any web server and configure the shared library endpoint for your environment. There is no build step to run.

Do you offer a student or open-source discount?

Pro is free for verified students and for maintainers of actively developed open-source projects. Write to us from the address on your profile page and we will set it up.