Privacy-first dev utilities for global teams

JSON, YAML, CSV, Markdown, QR, timestamps, encoding & regex — all executed locally in your browser. No accounts, no uploads: your payloads stay on your machine.

JSON Formatter

Format, minify, validate, sort keys, JSON → CSV.

XML tools

Format, minify, XML → JSON.

YAML ↔ JSON

Convert YAML configs to JSON and back.

CSV tools

Align columns, minify, CSV ↔ JSON.

Markdown preview

Live preview with safe rendering.

QR code

Generate QR codes and download PNG.

Timestamp

Unix ↔ ISO ↔ local time.

Image → Base64

Data URL and raw Base64 from images.

Base64 text

Encode and decode text as Base64.

URL encode/decode

Encode, decode, and parse URLs.

Regex tester

Match and replace preview.

HTML entities

Escape and unescape HTML entities.

UUID generator

Batch UUID v4 with Web Crypto.

Number bases

Convert integers between bases 2–36 (BigInt).

Color picker

HEX, rgb(), hsl() for CSS.

Guides for real workflows

Start with short tutorials when you need practical context, not just buttons.

JSON formatting best practicesBase64 encoding guideURL encoding explainedRegex for developersCSV and JSON conversionUnix timestamp guide

What Fast Toolkit is

Fast Toolkit is an editorially maintained collection of browser-based utilities for software engineers, site reliability engineers, technical writers, and curious makers. Each tool page explains not only which buttons to press but also why the operation matters, how your data stays on-device, and which limitations you should plan for when you move work back into production systems.

We built the suite around a simple promise: no accounts, no uploads of your payloads to our application servers. Parsing, formatting, rendering, and conversions execute with JavaScript inside your tab. That design supports sensitive workflows such as inspecting JSON from a private API or converting a customer’s CSV excerpt—as long as you still follow your employer’s data-handling policies and clear the page when you finish on a shared computer.

How we choose what to ship

Every utility solves a narrow problem we have hit repeatedly in real shipping work: messy JSON from logs, YAML copied out of Kubernetes, Markdown drafts that need a quick preview, QR codes for staging environments, timestamps pulled from distributed traces, and so on. We document edge cases directly on the page so you can decide whether this site or a heavier desktop tool is the right fit.

Using this site responsibly

  • Read the per-tool FAQ before you paste regulated data—even local tools cannot stop shoulder surfing.
  • Prefer dedicated secret managers for long-lived credentials; never treat Base64 or QR codes as encryption.
  • Combine these utilities with your normal code review, linting, and automated tests—think of Fast Toolkit as a notebook, not a compiler.

Transparency & ads

We may display Google AdSense or similar placements to fund hosting and ongoing improvements. Ads are configured to avoid intrusive formats wherever possible, and we publish a Privacy Policy describing analytics cookies. Tool logic still runs locally; advertising is orthogonal to your input.

Frequently asked questions

Do you store what I paste into the tools?
No. The tools are implemented as client-side scripts. Third-party analytics may record page views as described in our Privacy Policy.
Can I use Fast Toolkit offline?
After the first load, some browsers may cache assets, but you should assume network access is required unless you self-host the build.
How do I request a new tool?
Email hello@fasttoolkit.dev with a short user story—we read every message even if we cannot commit to a timeline.
Is commercial use allowed?
Yes, subject to any license file shipped with the repository if you fork the open-source build.
Why English copy?
English keeps guidance accessible to the widest international engineering audience while we iterate on localization.