5 Free Developer Tools Every Programmer Should Bookmark

Every developer has that graveyard of CLI tools they installed once and never opened again. The useful ones aren't clever or beautiful — they're just there when you need them. When JSON comes in as one long ugly string. When a URL is so percent-encoded you can't tell what it's supposed to say. When you need a throwaway password for staging and just want something, anything, right now.

This article covers five free browser tools worth bookmarking. All run locally — no signup, no upload, no npm install on a machine you do not control.

Why browser tools beat one-off scripts for small jobs

Writing a three-line Node script to prettify JSON is fine at your desk. It is less fine on a borrowed laptop, a phone, or a CI machine where you only have a browser. The pattern repeats: something lands in your clipboard, you need a transformation in under ten seconds, and opening a terminal feels like overkill.

Browser tools also win when the data is not yours to save. Pasting a API response fragment into a local formatter and closing the tab leaves no file on disk. That matters when you are debugging a client's payload on a shared screen share.

The trade-off is real: browser tools are not for batch processing a gigabyte log file. They are for the quick hits that interrupt your day — the ones that otherwise send you down a twenty-minute rabbit hole of "let me just install something real quick."

Tool 1: JSON formatter and validator

Messy JSON is the most common developer annoyance. Network tabs, webhook logs, and config snippets arrive minified or with a trailing comma that breaks parsers.

A good formatter does three things: prettify with readable indentation, minify for copy-paste into env vars, and show a clear error when the syntax is wrong. The error message matters more than pretty printing — "Unexpected token at position 847" beats staring at a blob.

We built ours with native JSON.parse — the same parser your browser uses for fetch responses. That means if it validates here, it will likely parse in your app too.

Use the JSON Formatter at TinyToolStudio — paste, format or minify, copy. If you are also tracing how that JSON gets transmitted, pair it with the URL encoder below for query string debugging.

Tool 2: Base64 encode and decode

Base64 shows up in JWT middle segments, data URIs, email MIME parts, and legacy API auth headers. Decoding by hand is not an option; installing base64 on every machine you touch is tedious.

The catch with Base64 in browsers is UTF-8. Emoji and non-ASCII text break naive btoa calls. A proper tool handles encoding correctly so you are not guessing whether the garbled output is bad data or bad decoding.

Our Base64 Encode / Decode tool switches between encode and decode with live output as you type — useful when you are iterating on a token and do not want to click a button after every edit.

Tool 3: URL encode and decode

Percent-encoding turns spaces into %20 and reserved characters into escape sequences. You need it when building query strings, debugging redirect URLs, or reading encoded parameters from analytics logs.

Decoding is equally common: someone sends you a %7B%22id%22%3A1%7D string and you need to see the JSON inside without squinting. A URL tool saves the round trip through decodeURIComponent in a console you may not have open.

Try the URL Encode / Decode tool — encode for building links, decode for reading them. It runs the same logic as JavaScript's built-in encode and decode functions.

Tool 4: Password generator

Not every password task belongs in 1Password. Test accounts, staging logins, and temporary API keys need random strings fast. Rolling your own with Math.random() is weak; opening a dedicated generator with length and character-set controls is better.

Look for uppercase, lowercase, numbers, and symbols as toggles. Copy-to-clipboard in one click. No account required — generated passwords should never touch a server.

The Password Generator on TinyToolStudio creates strong passwords locally. Use it for throwaway credentials, not as a replacement for a proper password manager on real accounts.

Tool 5: Case converter (bonus for API work)

Strictly speaking this is a text tool, but developers hit it constantly: snake_case API fields to camelCase for frontend code, kebab-case for URL slugs, UPPERCASE for environment variable names.

One paste, one click, copy the result. Faster than regex in a scratch file when you are already context-switching between five tabs.

The Case Converter handles uppercase, lowercase, title case, camelCase, snake_case, and kebab-case — all client-side.

How to organize these bookmarks

Create a browser folder called "Dev utilities" or pin the three you use daily. JSON formatter, Base64, and URL encode cover most clipboard emergencies. Add password generator when you are spinning up test environments.

If you work across machines, synced bookmarks beat installed tools — the formatter on your phone works the same as on your laptop.

When not to use browser tools

Do not paste production database credentials, live API secrets, or customer PII into random websites — even client-side ones — unless you trust the implementation. Read the page: if it says data stays in your browser, verify there is no network upload in dev tools.

For large files, automated pipelines, or repeatable scripts, CLI tools and IDE extensions still win. Bookmark the browser tools for the interrupts, not the infrastructure.