Simple tools for everyday development.

Open a tool, finish the task, and get back to work—without installs or signups.

269 toolsNo signupLocal-first

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269 tools

Popular Tools

AI Prompt PII & Secret Leak Scanner

Detect and redact sensitive data before sharing AI prompts

Browser P2P File Transfer

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

Screenshot Full Webpage

Capture public webpages as full-page or viewport images

XML to Java Class Converter

Convert XML to annotated Java classes with JAXB & Lombok support

SHA256 Hash Generator

Generate SHA256 hashes

JSON to TypeScript

Generate TypeScript interfaces

AI Coding Prompt Generator

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

Array Sorter & Shuffler

Sort and shuffle arrays and objects

AI

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.

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

AI Agent Workflow Generator

Generate maintainable coding-agent instructions, skills and workflows.

Prompt Injection Checker

Check prompts, external context, and agent boundaries for injection risk

RAG Chunker

Split documents into retrieval chunks by tokens, sentences or Markdown structure and inspect overlap

AI Tokenizer Explorer

See how text becomes tokens, with IDs, bytes and offsets

Product & Analytics

Mixpanel Toolkit

Local Mixpanel event sandbox

Engineering Task Compiler

Compile rough requirements into execution-ready engineering tasks.

PRD Generator

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

A/B Test Calculator

Plan sample size and check A/B test significance with SRM detection.

Feature Flag Rollout Planner

Plan staged feature flag rollouts with users per stage, guardrails and a deterministic bucketing simulator.

Converters

YAML ⇄ JSON Converter

Convert between YAML and JSON

CSV ⇄ JSON Converter

Convert between CSV and JSON

XML ⇄ JSON Converter

Convert between XML and JSON formats

HTML to Markdown Converter

Convert HTML and webpages into clean Markdown

SVG to JSX

Convert SVG markup into clean React JSX or TSX components

CSV to Markdown

Convert CSV into Markdown tables or compact AI-ready context

JSON to Table

View JSON arrays and API responses as a sortable, searchable table

JSON to Excel Converter

Convert JSON arrays into a real .xlsx workbook with a preview first

JSON to Markdown

Convert JSON into Markdown tables, readable sections or AI context

JSON Flattener

Flatten nested JSON into path keys and unflatten it back

JSON ↔ SQL Converter

Turn JSON into CREATE TABLE and INSERT statements, or SQL INSERT data into JSON

TSV ⇄ JSON Converter

Convert TSV pasted from Excel or Google Sheets to JSON, and JSON back to TSV

Query Params ⇄ JSON Converter

Convert URL query strings to JSON and JSON back to query strings, with repeated keys and Unicode intact

.env to Netlify TOML

Turn a .env file into a netlify.toml environment block for any Netlify deploy context

JSONC to JSON

Convert JSONC and JSON5 to strict JSON

Excel to JSON Converter

Turn .xlsx, CSV and TSV sheets into API-ready JSON in your browser

JSON ↔ Protobuf Toolkit

Infer .proto schemas from JSON, or encode and decode Protobuf payloads with your schema

JSON ↔ TOON Converter

Convert JSON to TOON and back for compact LLM prompts

Docker Run ↔ Compose Converter

Convert docker run commands to Compose YAML and back, with a report of what converted

OPML ↔ RSS/Atom Feed List Converter

Extract feeds from OPML or build OPML from a list of feed URLs

JSON ↔ TOML Converter

Convert JSON to TOML and TOML to JSON with every lossy change listed

Markdown to HTML

Convert CommonMark or GitHub Flavored Markdown into clean HTML

Code Generators

JSON to TypeScript

Generate TypeScript interfaces

UUID/GUID Generator

Generate unique identifiers instantly

Fake Data Generator

Generate mock data

XML to Java Class Converter

Convert XML to annotated Java classes with JAXB & Lombok support

Form Validation Generator

Design validation once and generate framework-neutral code.

JSON to Zod

Generate Zod schemas from JSON

CSS Flexbox Generator

Build Flexbox layouts visually and copy CSS, HTML or Tailwind

JSON Schema Generator

Infer a Draft 2020-12 JSON Schema from sample JSON

JSON to Python

Generate Python dataclasses, Pydantic models or TypedDicts from JSON

JSON to Java

Generate Java POJOs, records or Lombok classes from JSON

JSON to Go

Generate Go structs with JSON tags from JSON

JSON to Swift

Generate Swift Codable structs or classes from JSON

JSON to Rust

Generate Rust structs with Serde attributes from JSON

JSON to PHP

Generate typed PHP classes with fromArray() from JSON

JSON to C#

Generate C# classes or records for System.Text.Json or Newtonsoft.Json

.htaccess Generator

Build Apache .htaccess redirects, caching and security rules with conflict checks

CSS Grid Generator

Build CSS Grid layouts visually and copy clean CSS and HTML

CSS Confetti Generator

Design confetti animations and copy lightweight HTML, CSS and JS

JSON to Kotlin

Generate Kotlin data classes from JSON for kotlinx.serialization, Gson, Moshi or Jackson

ULID Generator & Inspector

Generate sortable ULIDs and decode their timestamps

Editors

Markdown Editor & Previewer

Live markdown editor with preview

CSV Editor

Edit CSV files like a spreadsheet

YAML Viewer

View, parse, and validate YAML with tree view

HTML CSS JS Playground

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

WebAssembly Playground

Write WAT, compile it to WebAssembly, inspect the binary, and call exported functions locally.

Formatters

JSON Formatter

Format and beautify JSON data

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

Array Sorter & Shuffler

Sort and shuffle arrays and objects

JSON Sorter

Sort JSON keys alphabetically

SQL Formatter & Minifier

Format or safely minify SQL in eight dialects without touching string literals

JSON Repair

Fix broken JSON from LLMs, logs and JavaScript objects

CSS Inliner for Email

Inline CSS into email HTML with a correct cascade, kept media queries and a safe preview

XML Formatter & Validator

Beautify, minify, and validate XML locally

Debug & Validate

JSON Schema Validator

Validate JSON against schemas

Regex Tester

Test regular expressions interactively

Source Map Stack Trace Resolver

Decode minified stack traces with source maps

Big O Complexity Analyzer

Estimate time and space complexity in 14 languages with confidence and evidence. Syntax trees for JS, TS and Python; bounded heuristics for other languages.

JSON Search

Find where any key or value appears in nested JSON

PHP Unserializer

Inspect PHP serialized values safely without executing PHP code

JSON Query Playground

Run real jq on JSON and JSONL in your browser and see the output as you type

JSON Log Viewer & Analyzer

Open, search and filter JSONL, NDJSON and Docker JSON logs in your browser with a fast virtualized event list

PostgreSQL EXPLAIN Visualizer

Turn EXPLAIN ANALYZE JSON into a readable plan tree with timing, estimates and buffers

JSONPath Query Playground

Test RFC 9535 JSONPath queries and see every match with its path

Stack Trace Analyzer

Error chains, root cause and app frames from any stack trace

Regex Library

Tested regex patterns for every language

XML Schema (XSD) Validator

Validate XML against an XSD 1.0 schema in your browser

Diff

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

ENV Diff Comparator

Compare, audit & merge .env files with secret detection

PDF Diff Checker

Compare PDF text, pages, and visual changes locally

Image Diff Checker

Compare screenshots and inspect visual regressions pixel by pixel

Excel Diff Checker

Compare two Excel workbooks sheet by sheet, row by row and cell by cell

API

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

cURL to Code Converter

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

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

HAR File Viewer

Inspect HAR network logs as a waterfall or table, with secrets masked

OpenAPI Diff & Breaking Change Checker

Compare two OpenAPI or Swagger specs and flag breaking API changes

CORS Tester & Policy Analyzer

Test CORS in your browser or simulate a preflight with any Origin

Cache-Control Analyzer & Builder

Explain Cache-Control headers for browsers and CDNs, then build one from TTLs

GraphQL API Tester

Send GraphQL queries and mutations, then inspect the response, errors and schema

WebSocket & SSE Tester

Connect to WebSocket and Server-Sent Events endpoints from your browser and inspect every message live.

API Mock Server

Mock REST API routes with rules, delays, scenarios and a temporary public endpoint

URL Parser

Inspect URL components and ordered query parameters locally.

Network

Local Port Scanner

Automatically find localhost development servers

CIDR / Subnet Calculator

IPv4 and IPv6 subnet math, address types and subnet splitting

TCP / UDP Port Lookup

Look up any port for its official IANA assignment and common developer uses

IPv4 Address Converter

Convert IPv4 between dotted, integer, hex and binary forms

IPv4 Range & CIDR Calculator

Convert IPv4 ranges to the minimal CIDR list, list their addresses, or expand a CIDR block

IPv6 Parser

Expand, compress and inspect any IPv6 address

IPv6 ULA Generator

Random RFC 4193 unique local /48 prefixes with /64 subnets

MAC Address Vendor Lookup

Find the vendor behind a MAC address and decode its address bits

TLS Endpoint Inspector

Check TLS 1.0 to 1.3 support, cipher, ALPN and the served certificate for one public host

Web Detectors

Web Technologies Detector

Find a website's publicly detectable tech stack with evidence

Subdomain Finder

Find public subdomains and verify DNS records

Website Font Inspector

Find the fonts a website declares, loads and renders

Security

JWT Decoder

Decode JWT tokens

Password Generator

Generate secure passwords

JWT Generator

Generate JWT tokens with HS256

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

SQL Injection Lab

Learn how unsafe SQL differs from parameterized queries

Random String & Token Generator

Generate secure random strings, API keys and tokens with honest entropy

RBAC Analyzer

Find role hierarchy cycles, redundant grants and separation-of-duty conflicts

Cookie Analyzer

Check Set-Cookie headers for Secure, HttpOnly, SameSite and prefix issues

OAuth 2.0 & OIDC Debugger

Build, inspect and fix OAuth and OIDC flows

CSP Analyzer & Builder

Check a Content-Security-Policy for weaknesses or build a strong starting policy

JWK ↔ PEM Converter

Convert JWK and JWKS keys to SPKI or PKCS#8 PEM and back

X.509 Certificate Inspector

Decode PEM and DER certificates and check expiry, SANs and chain order

Webhook Signature Verifier

Verify GitHub, Stripe, Slack, Shopify and Standard Webhooks signatures and see why they fail

Passkey / WebAuthn Debugger

Test passkeys in your browser and decode WebAuthn responses offline

SAML Decoder

Decode SAMLRequest and SAMLResponse from POST, Redirect or raw XML

SAML Metadata Parser

Inspect IdP, SP and federation metadata: endpoints, certificates and issues

SAML Response Validator

Check SAML timestamps, audience, destination and recipient

Secret & API Key Scanner

Find leaked API keys, tokens and passwords in code, config, logs and diffs, then redact them

Bcrypt Hash Generator

Generate salted bcrypt hashes or verify a password locally.

HMAC Generator

Authenticate messages with a shared secret

RSA Key Pair Generator

Generate RSA public and private keys as PEM in your browser

Encoding & Hashing

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

MD5 Generator

Generate MD5 hash from text or files

SHA256 Hash Generator

Generate SHA256 hashes

SHA512 Hash Generator

Generate SHA512 hashes

Image ↔ Base64 Converter

Convert images to Base64 and decode Base64 back to images

Emoji Picker

Find, copy, and inspect Unicode emoji

Backslash Escape / Unescape

Escape and unescape backslash sequences for Common, JSON and JavaScript strings

Endianness Converter

Swap byte order in 16, 32 or 64-bit words and read big-endian and little-endian values.

CRC & Checksum Calculator

Calculate CRC-8, CRC-16, CRC-32, CRC-64 and Adler-32 for text, hex bytes or files.

Text ↔ Binary Converter

Convert text and binary bytes with UTF-8 or strict ASCII.

Developer Workflow

Commit Message Generator

Generate conventional commits

Cron Expression Generator

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

Gitignore Generator

Generate production-ready .gitignore files for any tech stack

SemVer Release Advisor

Decide the exact next version from your release changes

Dev Service Status

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

Git Worktree Generator

Visual Git worktree workflow planner and command generator

Database Connection String Builder & Parser

Build and parse PostgreSQL, MySQL, MongoDB, Redis, SQL Server and SQLite connection strings

GitHub Actions Workflow Validator

Lint GitHub Actions workflows with actionlint and catch risky permissions and refs

Kubernetes Manifest Inspector & Linter

Lint Kubernetes YAML for schema, API, security and selector issues

SQLite Database Browser

Open a SQLite file in your browser, browse tables and schema, and run SQL on a working copy

MIME Type Lookup

Find the MIME type for any file extension, with IANA status and Content-Type snippets

Git Branch Name Generator

Turn task titles and ticket keys into valid Git branch names

Chmod Calculator

Calculate and parse Unix permissions from 000 to 777.

SEO

Schema Markup Builder & Validator

Build and validate JSON-LD schema markup with live checks

Broken Link Checker & Cleaner

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

SEO & Social Metadata Previewer

Preview Google search snippets and social cards from a page's title, description, and Open Graph tags

Open Graph Image Builder

Create branded social preview images and metadata-ready assets

PWA Inspector

Audit manifests, icons, installability, and common PWA issues

Web Accessibility Checker

Run automated WCAG 2.2 checks on a public URL or HTML and get actionable findings

AI Crawler Access Tester

Check how robots.txt and page directives treat search and AI crawlers

Robots.txt Tester & Builder

Test URLs against robots.txt, trace the deciding rule and build a valid file

XML Sitemap Builder & Validator

Build, split and validate XML sitemaps, then check URL health

SEO Rendering & Indexability Inspector

Compare Static HTML with the Rendered DOM and find indexability issues

Hreflang Validator & Generator

Check hreflang clusters, return links and codes, then generate tags

RSS / Atom Feed Inspector

Validate RSS and Atom feeds, review items and export the results

Meta Tag Generator

Generate SEO, Open Graph and X meta tags with live previews

SEO Meta Inspector

Check a page’s title, description, canonical, robots, Open Graph and X tags

Social Media

GitHub Profile README Builder

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

Profile Picture Badge Generator

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

LinkedIn Carousel Generator

Design editable LinkedIn PDF carousels in a horizontal WYSIWYG workspace

LinkedIn Post Previewer

Format and preview LinkedIn posts on desktop and mobile

Text

String Case Converter

Convert text case formats

Lorem Ipsum Generator

Generate placeholder text for your designs instantly

Word Counter

Count words, characters, sentences and paragraphs instantly

Tech Workplace Dictionary

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

Sort & Dedupe Lines

Sort lines and remove duplicates like sort and uniq

Whitespace Remover & Normalizer

Remove, trim and collapse spaces, tabs and blank lines safely

Text to NATO Phonetic Alphabet

Spell letters with the NATO alphabet

Documents

ATS CV/Resume Builder

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

PDF to Markdown

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

PDF Splitter

Split a PDF into separate files or extract pages in your browser

PDF Page Manager

Reorder, rotate, and delete PDF pages visually

PDF Merger

Combine PDFs in any order and pick the pages from each file

Image to PDF

Turn photos and scans into one PDF with the page size you need

PDF Compressor

Shrink PDFs in your browser and see exactly how much was saved

PDF Watermark

Stamp text or a logo onto PDF pages without flattening them

Add Signature to PDF

Draw, type, or upload a signature and place it on any PDF page

PDF to Image

Render PDF pages to PNG, JPEG, or WebP images in your browser

PDF to Text & OCR

Extract text from digital and scanned PDFs, with OCR only when needed

PDF to DOCX Converter

Convert PDF to an editable Word document or a page-image copy that keeps the look

Resignation Letter Generator

Write a clear resignation letter or email with the right last working day

Images

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

Screenshot Full Webpage

Capture public webpages as full-page or viewport images

Screenshot Image Annotator

Highlight, explain, redact, and present screenshots

SVG to Image

Convert SVG to sharp PNG, JPEG, WebP, or AVIF images at any size

Image Compressor

Compress JPEG, PNG, and WebP images locally in your browser

Image Resizer

Batch resize images by percentage, exact size, or max dimensions

Image Format Converter

Convert images between PNG, JPEG, WebP, and AVIF in your browser

Image Cropper

Crop images to exact sizes and aspect ratios

Image Watermark

Add text or logo watermarks to images in bulk

Favicon Generator

Generate favicon.ico, Apple touch, Android, and maskable icons with a manifest

Background Remover

Remove solid image backgrounds locally by color

Image Filters

Apply precise photo filters and export full-resolution images locally

Graphics

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

Markdown to Infographic

Turn structured Markdown into editable, deterministic infographics

Blob Generator

Generate organic SVG blob shapes from a reproducible seed

SVG Wave Generator

Create single or layered SVG wave dividers with responsive output

Avatar Generator

Create seeded avatars in six styles, from initials and geometric patterns to animals, characters and professions. Export SVG or PNG locally.

Image Placeholder Generator

Create placeholder images with live preview, size presets and offline snippets

Logo Placeholder Generator

Placeholder logos for mockups and prototypes, with deterministic seeds

Barcode Generator

Create Code 128, EAN-13, UPC-A and ITF-14 barcodes as SVG or PNG

CSV Chart Plotter

Turn CSV into bar, line, area, donut or scatter charts

WiFi QR Code Generator

Create a QR code that joins a WiFi network when scanned

Color

Color Converter

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

Gradient Generator

Browse curated CSS gradients or build linear, radial, and conic ones

Image Color Extractor

Pick exact pixel colors and extract dominant palettes from any image

Color Palette Generator

Build lockable harmony palettes, OKLCH tonal scales and design tokens

WCAG 2.2 Color Contrast Checker

Check text and UI color contrast against WCAG 2.2 AA and AAA, then fix failing pairs

Transfer & Calls

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.

Animated QR File Transfer

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

Media

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.

Speech to Text

Transcribe your microphone or audio files with a local model or browser recognition

Screen Recorder

Record a tab, window or screen with audio, locally in your browser

Video Trimmer

Trim a browser-decodable video without uploading it

Webcam Recorder

Record video and take native PNG snapshots in your browser

Device & Browser

Internet Speed Test

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

User Agent Parser

Parse any User-Agent string into browser, OS, device, and bot details

Fullscreen Screen Tools

Screen tests, fullscreen colors, screensavers, visual simulators, and harmless prank screens

Mouse Tester

Check mouse buttons, wheel, double clicks and CPS in your browser

Headphone Tester

Check left and right headphone channels with safe test tones

Webcam Tester

Check your camera, resolution, FPS and lighting in the browser

Keyboard Tester

Check every key on a physical keyboard in your browser

Responsive Window Resizer

Open any page in a test window at an exact viewport size

Device & Browser Information

See what your browser exposes for support and debugging

Time

Unix Timestamp Converter

Convert timestamps to dates

Timezone Converter

Convert between timezones

ISO8601 Formatter

Format and parse ISO8601 dates

Age Calculator

Calculate age from birth date

Work Hours Calculator

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

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.

Day of the Year Calculator

Find which day of the year any date is

Productivity

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.

Pomodoro Timer

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

Wheel of Names

Random Name Picker & Wheel Spinner

Numbers

Unit Converter

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

Decimal Precision Calculator

Precise decimal calculations

Number to Words Converter

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

Number Base Converter

Convert integers exactly between binary, octal, decimal, hex and any base from 2 to 36

Roman Numeral Converter

Convert numbers and Roman numerals

Finance

Currency Formatter

Format currency values

Invoice Generator

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