The best developer tools are the ones you don't have to install. No npm install, no Homebrew tap, no license key. Just open a tab, do the thing, close the tab.
Here are 10 browser-based tools that live permanently in my bookmarks bar — all free, all instant, all no-sign-up.
1JSON Formatter & Validator
Paste minified JSON and instantly see it formatted, validated, and tree-navigable. Catches missing commas, unquoted keys, and mismatched brackets before your parser does.
ficktools → JSON FormatterRegex Tester
Write a regular expression and test it against live input with real-time match highlighting. Supports flags (global, multiline, case-insensitive) and shows capture groups.
ficktools → Regex TesterBase64 Encoder / Decoder
Encode strings for API authentication headers or decode opaque tokens instantly. Also handles URL-safe Base64 and binary file encoding.
ficktools → Base64 ToolCSS Box Shadow Generator
Drag sliders to build layered, color-tinted shadows and copy the CSS box-shadow property. Supports multiple shadow layers and live preview on any background color.
CSS Gradient Generator
Build linear, radial, and conic gradients visually — then copy the background CSS. Stack multiple gradients and adjust stops without touching code.
Text Diff Checker
Paste two versions of a file or config and see added, removed, and unchanged lines highlighted side by side. Useful for reviewing API response changes or config diffs.
ficktools → Diff CheckerURL Encoder / Decoder
Encode special characters for query strings or decode percent-encoded URLs. Handles both encodeURI and encodeURIComponent modes.
Hash Generator (MD5, SHA-256, SHA-512)
Generate cryptographic hashes for integrity checking, password verification concepts, and API signature testing. Everything runs in the browser — nothing is sent to any server.
ficktools → Hash GeneratorMarkdown Editor with Live Preview
Write and preview Markdown side by side. Export to HTML. Perfect for drafting README files, documentation, or blog posts without firing up a full editor.
ficktools → Markdown EditorUUID Generator
Generate cryptographically random UUID v4 strings one at a time or in bulk. Copy single values or export a list — useful for seeding databases or populating mock data.
ficktools → UUID GeneratorWhy These Over Alternatives?
There are dozens of sites offering similar tools. The differentiator with ficktools is simple: no sign-up, no ads, no data sent to servers. Every tool on this list processes your data locally in the browser. That matters when you're pasting API keys, internal JSON payloads, or private configuration files.
Speed also matters. Each tool loads in under a second on any connection — no bloated frameworks, no tracking scripts adding latency to every keystroke.