All Developer Tools

Browse our complete collection of 104 free online developer tools. Most run locally, and every tool discloses whether it uses local, hybrid, or server processing.

AI Tools

6 tools

AI Prompt PII & Secret Leak Scanner

Detect and redact sensitive data before sharing AI prompts

AI Coding Prompt Generator

Choose what you want the AI to do and get a prompt structured for that coding task.

Engineering Task Compiler

Compile rough requirements into execution-ready engineering tasks.

LLM Cost & Context Planner

Estimate prompt, agent, and production LLM costs before you run them

AI Coding Tools Directory

Find the right AI tool for coding, reviewing, testing, debugging, and shipping software

AI Usage & Rate Limit Tracker

See every AI coding quota, reset, usage pace, and capacity risk in one local-first dashboard

JSON Tools

4 tools

JSON Formatter

Format and beautify JSON data

JSON Schema Validator

Validate JSON against schemas

JSON to TypeScript

Generate TypeScript interfaces

Array Sorter & Shuffler

Sort and shuffle arrays and objects

CSV & Tables

2 tools

CSV ⇄ JSON Converter

Convert between CSV and JSON

CSV Editor

Edit CSV files like a spreadsheet

XML & YAML

4 tools

YAML ⇄ JSON Converter

Convert between YAML and JSON

XML ⇄ JSON Converter

Convert between XML and JSON formats

YAML Viewer

View, parse, and validate YAML with tree view

XML to Java Class Converter

Convert XML to annotated Java classes with JAXB & Lombok support

Web & Code

7 tools

JavaScript Beautifier & Minifier

Format or minify JavaScript

CSS Beautifier & Minifier

Format, optimize, and minify CSS code

HTML Beautifier & Minifier

Format, optimize, and minify HTML code

Regex Tester

Test regular expressions interactively

Source Map Stack Trace Resolver

Decode minified stack traces with source maps

Color Converter

Convert colors across CSS, mobile, and design-token formats

HTML CSS JS Playground

Write frontend code, run it safely, and debug the result in your browser.

SEO & Web Analysis

3 tools

Schema Markup Validator

Validate JSON-LD schema markup and rich result readiness

Broken Link Checker & Cleaner

Find, remove, and replace dead URLs from text, files, and webpages

Open Graph Previewer

Preview social cards and debug Open Graph, Twitter Card, and HTML metadata

Text & Markdown

6 tools

String Case Converter

Convert text case formats

Markdown Editor & Previewer

Live markdown editor with preview

Lorem Ipsum Generator

Generate placeholder text for your designs instantly

Word Counter

Count words, characters, sentences and paragraphs instantly

HTML to Markdown Converter

Convert HTML and webpages into clean Markdown

PDF to Markdown

Convert PDFs into clean, AI-ready Markdown for coding agents

Images & QR

9 tools

QR Code Generator

Generate QR codes instantly from URLs, text, or JSON — no backend needed

Code Screenshot Generator

Create beautiful, shareable images of your code

Image to WebP Converter

Convert images to WebP format instantly in your browser

Screenshot to Text & Code

Extract text and code from screenshots with local OCR

Animated QR File Transfer

Transfer small files through animated QR codes with no upload, account, network, or pairing.

Profile Picture Badge Generator

Add an available-for-work, hiring, freelancer, event, or custom badge to your profile picture.

Open Graph Image Builder

Create branded social preview images and metadata-ready assets

Screenshot Image Annotator

Highlight, explain, redact, and present screenshots

LinkedIn Carousel Generator

Design editable LinkedIn PDF carousels in a horizontal WYSIWYG workspace

Browser & Media

5 tools

Screenshot Full Webpage

Capture public webpages as full-page or viewport images

Browser P2P File Transfer

Send files directly between two browsers using WebRTC. No upload, no account, no server storage.

Browser Video Call

Make a direct one-to-one P2P video call with screen sharing and private browser-to-browser chat.

Video Picture-in-Picture

Keep a local video, direct URL, webcam, or screen capture visible while you work.

Music Player

Play private local audio, arrange a playlist, and keep compact controls visible while you work.

Numbers & Units

3 tools

Age Calculator

Calculate age from birth date

Unit Converter

Developer-focused unit converter for data sizes, rates, time, and more

Decimal Precision Calculator

Precise decimal calculations

Hashing

3 tools

MD5 Generator

Generate MD5 hash from text or files

SHA256 Hash Generator

Generate SHA256 hashes

SHA512 Hash Generator

Generate SHA512 hashes

Encoding & Escaping

4 tools

Base64 Encoder & Decoder

Encode text to Base64 or decode Base64 back to text

URL Encoder & Decoder

Encode text to URL-safe format or decode percent-encoded strings back to text

HTML Escape & Unescape

Encode HTML entities or decode them back — in one workspace

Image ↔ Base64 Converter

Convert images to Base64 and decode Base64 back to images

Credentials & Privacy

7 tools

JWT Decoder

Decode JWT tokens

Password Generator

Generate secure passwords

JWT Generator

Generate JWT tokens with HS256

ENV Diff Comparator

Compare, audit & merge .env files with secret detection

ZIP with Password

Compress & encrypt files locally — no upload, no server.

Password Strength Checker

Test password strength and predictable patterns privately

PDF PII & Secret Redactor

Detect and permanently remove secrets before sharing a PDF

API & Networking

12 tools

HTTP Header Parser

Parse HTTP headers

Swagger / OpenAPI Viewer

Visualize and explore OpenAPI 3.x and Swagger 2.0 specs instantly

Mini Postman (API Tester)

Test REST APIs directly in your browser — no install needed

Internet Speed Test

Check download speed, latency, jitter, and upload availability from your browser

Mixpanel Toolkit

Local Mixpanel event sandbox

cURL to Code Converter

Convert HTTP requests across cURL, code, HAR, and structured formats with local secret protection.

Local Port Scanner

Automatically find localhost development servers

Dev Service Status

Check GitHub, OpenAI, Claude, Vercel, Cloudflare, npm and other developer services in one place.

Web Technologies Detector

Find a website's publicly detectable tech stack with evidence

Subdomain Finder

Find public subdomains and verify DNS records

HAR to Markdown

Compile sanitized network logs for backend debugging and AI agents

HAR to OpenAPI

Generate a reviewable OpenAPI contract from sanitized browser traffic

Time & Scheduling

4 tools

Unix Timestamp Converter

Convert timestamps to dates

Timezone Converter

Convert between timezones

ISO8601 Formatter

Format and parse ISO8601 dates

Cron Expression Generator

Build, validate, and visualize cron schedules with timezone-aware simulation

Productivity

5 tools

Work Hours Calculator

Calculate work hours, WFO/WFH count, leave, business trips, client visits, and overtime using your company rules.

Pomodoro Timer

Run accurate focus and break cycles, track daily progress, and keep the timer visible.

Stopwatch

Measure drift-free elapsed time, record lap statistics, and save or export sessions locally.

Event Countdown

Create precise, time-zone-aware countdowns, count-ups, and date-range progress trackers.

Wheel of Names

Random Name Picker & Wheel Spinner

Document

3 tools

Document Picture-in-Picture

Upload or open a document and keep its scrollable preview visible while you work.

Floating Notes

Write private notes and checklists that autosave locally and stay visible in a floating view.

ATS CV/Resume Builder

Create, verify, score, and export an ATS-friendly resume

Financial

3 tools

Currency Formatter

Format currency values

Number to Words Converter

Convert numbers to words in English and Indonesian with currency and check writing support

Invoice Generator

Create professional PDF invoices locally with accurate totals, branding, and reusable history.

Developer Workflow

10 tools

UUID/GUID Generator

Generate unique identifiers instantly

Fake Data Generator

Generate mock data

Commit Message Generator

Generate conventional commits

Gitignore Generator

Generate production-ready .gitignore files for any tech stack

GitHub Profile README Builder

Build a credible, project-first GitHub profile README that stays clean and GitHub-safe

Form Validation Generator

Design validation once and generate framework-neutral code.

SemVer Release Advisor

Decide the exact next version from your release changes

Tech Workplace Dictionary

Understand the terminology, acronyms, jargon, and phrases used by modern tech teams

Git Worktree Generator

Visual Git worktree workflow planner and command generator

PRD Generator

Create, save, and reopen structured PRDs in your browser, starting blank or from complete template PRDs

Compare & Validate

4 tools

Code Diff Checker

Compare code/text side-by-side

JSON Diff Checker

Spot every change between two JSON objects instantly

CSV Diff Checker

Compare two CSV files with key-based diff and field-level change detection

PDF Diff Checker

Compare PDF text, pages, and visual changes locally

Explore Developer Workflows

Browse focused collections, common development tasks, and practical tool comparisons.

Tool Categories

Explore tools grouped by technical domain.

Use Cases

Start from the development task you need to complete.

Tools for Debugging Code Formatting Tools Data Conversion Tools API Development Tools Hashing & Security Tools Text Processing Tools

Tool Comparisons

Choose the right workflow for your data and security needs.

JSON Formatter vs JSON Validator YAML vs JSON Converter MD5 vs SHA-256 Hash Generator JWT Decoder vs JWT Generator Base64 vs URL Encoding CSV vs JSON Format Comparison

Why Use Our Developer Tools?

🔒 Privacy-First

Processing boundaries are shown on every tool. Local tools keep tool input on your device; network-dependent tools disclose when a request leaves the browser.

⚡ Lightning Fast

Local tools provide immediate results and may work after the page loads. Network-dependent features identify when connectivity is required.

🆓 100% Free

No registration, no subscriptions, no hidden fees. All tools are completely free to use without any limitations.

🌍 Multi-Language

Available in 10 supported languages including English, Chinese, Japanese, Russian, and more. Choose your preferred language anytime.

Popular Tool Categories

Data Formats: Format, validate, and convert JSON, YAML, CSV, XML, and tabular data
Web & Code: Test regex, format code, run browser playgrounds, and resolve stack traces
SEO & Web Analysis: Preview OpenGraph metadata, validate schema markup, and check broken links
Text & Markdown: Edit Markdown, transform HTML, count words, and process text
Browser & Media: Use Picture-in-Picture, browser transfers, video calls, screenshots, and media tools
Productivity: Run Pomodoro sessions, track time, plan countdowns, and pick names fairly
Security & Privacy: Generate hashes, passwords, JWTs, and privacy-safe credentials

How to Use Our Tools

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