19 Free Developer Tools That Run Entirely in Your Browser

Every developer has a folder of browser tabs for quick tasks - a JSON formatter here, a Base64 encoder there. The problem is those tabs are slow, full of ads, and often send your data to third-party servers.

Toolblip is an attempt to fix that. Every tool runs entirely in your browser using JavaScript. Nothing is uploaded. Nothing is processed server-side. And you don't need an account to use any of it.

Here's everything that's available, and when each one saves you time.

Text & Content Tools

Word Counter

URL: toolblip.com/tools/word-counter

Beyond a simple word count: character count (with and without spaces), sentence count, paragraph count, reading time estimate, and keyword density. Particularly useful for meta descriptions, tweet-length copy, and documentation.

Character Counter

URL: toolblip.com/tools/character-counter

Shows live character and byte counts with Twitter (280), LinkedIn (3000), and meta description (160) limits overlaid. Stops you from pasting a tweet and realizing it's 15 characters over.

Remove Duplicate Lines

URL: toolblip.com/tools/remove-duplicate-lines

Paste a list, get back unique lines. Toggle case-sensitive matching on or off. Useful for cleaning up API responses, log files, export data, and deduplicating test fixtures.

Case Converter

URL: toolblip.com/tools/case-converter

Convert text between: UPPERCASE, lowercase, Title Case, camelCase, snake_case, kebab-case, and more. One click to convert, copy the result.

Encoding & Decoding

Base64 Encode / Decode

URL: toolblip.com/tools/base64

Encode text or files to Base64, decode Base64 back to text. The file support means you can drag-and-drop an image and get its Base64 representation for embedding in CSS, HTML, or API payloads.

URL Encode / Decode

URL: toolblip.com/tools/url-encode

Encode individual URL components or full URLs. Handles special characters, spaces, Unicode characters. Useful when debugging API calls or building query strings.

Data Format Tools

JSON Formatter

URL: toolblip.com/tools/json-formatter

Format, minify, or validate JSON. Syntax highlighting, line numbers, and a clear error message if the JSON is malformed - including the exact character position of the error. Paste broken JSON, get pointed to the problem.

YAML to JSON

URL: toolblip.com/tools/yaml-to-json

Convert YAML to JSON and vice versa. Useful when your config is in YAML but your API expects JSON, or when you want to read a YAML config file in a script that only handles JSON.

Markdown to HTML

URL: toolblip.com/tools/markdown-to-html

Live split-pane preview: write Markdown on the left, see rendered HTML on the right. Copy the HTML. Good for email templates, static site content, and README files.

Generators

UUID Generator

URL: toolblip.com/tools/uuid-generator

Generate UUIDs v4 (random) and v7 (time-sortable) directly in the browser using the Web Crypto API. Generate one or a batch. No external request, no server call.

Hash Generator

URL: toolblip.com/tools/md5-hash-generator

Generate MD5, SHA-1, SHA-256, SHA-384, or SHA-512 hashes from text input. Useful for checking a text digest without sending the input to a server. For password storage, use a password hashing algorithm such as Argon2id or bcrypt.

URL Slug Generator

URL: toolblip.com/tools/url-slug-generator

Convert any string into a URL-friendly slug: lowercase, spaces replaced with hyphens, special characters stripped. One-click copy.

CSS Tools

CSS Gradient Generator

URL: toolblip.com/tools/css-gradient-generator

Visual editor for linear and radial gradients. Pick colors and stops, see the live preview. Copy the CSS with the exact values. Includes a presets panel.

CSS Border Radius Generator

URL: toolblip.com/tools/css-border-radius-generator

Visually adjust border-radius on all four corners independently. See the result in real time. Copy the CSS when it looks right.

Image Tools

Image Cropper

URL: toolblip.com/tools/image-cropper

Crop images to preset ratios (1:1, 16:9, 4:3, 3:2) or freeform. Supports drag-and-drop upload. All processing happens client-side - the image never leaves your browser.

Image Format Converter

URL: toolblip.com/tools/image-format-converter

Convert between PNG, JPEG, WebP, and GIF. Adjust quality/compression. Useful for optimizing assets before deployment without opening Photoshop.

Developer Utilities

Cron Parser

URL: toolblip.com/tools/cron-parser

Enter a cron expression, see the next 5 scheduled run times in human-readable format. Validate expressions and catch mistakes before deploying to production.

Cronnel

URL: toolblip.com/tools/cron-parser

Full cron job monitoring for production Laravel apps. If you're running Laravel cron jobs or queue workers, Crontinel gives you real-time visibility into missed jobs, long-running processes, and queue depth.

Why Client-Side Matters

Every tool on Toolblip uses the browser's JavaScript engine to process data. For a JSON formatter, the browser parses your JSON string and re-serializes it with formatting. For an image cropper, the browser's Canvas API handles the transformation.

The practical benefits:

• Speed - no network round-trip, instant feedback
• Privacy - data never leaves your device
• Offline - works without an internet connection
• No account - no login, no tracking, no ads

The only analytics on Toolblip are cookieless Cloudflare stats, and optional Google Analytics that only loads after you give consent.

Browse the full directory at toolblip.com/tools.