Developer Utilities

A

Allthatconverter

Free

A pile of free online tools, no ads: image, audio, video, PDF, text, typing practice

W

Web SSH

Free

Lightweight SSH client that runs in the browser

C

C-SSH

개발자 직접 추천입니다. C-SSH는 SSH 원격 터미널, 지속 세션, 서버 관리, RDP 원격 데스크톱, 파일 관리와 모니터링을 통합한 무료 서버 운영 클라이언트입니다. 선택적으로 AI 운영 지원을 사용할 수 있습니다. 현재 0.9.0은 Windows x64, Apple Silicon Mac, Android arm64용이며 플랫폼별 기능이 다릅니다. 클라이언트는 비공개 소스이고, AI 모델 제공업체의 이용 요금은 별도일 수 있습니다. 한국어 UI를 지원합니다. 설치 전에 공식 웹사이트와 공개 문서·스크린샷에서 기능을 확인할 수 있습니다: https://github.com/suiyuebaobao/C-SSH

I

IT Tools

Free

Open-source collection of dozens of developer utilities like hashing, encoding and conversion

A

axios

Free

A promise-based HTTP client that works in both the browser and Node.js.

T

Tauri

Free

A framework for building small, fast desktop and mobile apps with a web frontend, a lighter alternative to Electron.

T

TypeScript

Free

A typed superset of JavaScript that compiles to plain JavaScript, used to catch errors early in large codebases.

D

D3.js

Free

A JavaScript library for binding data to SVG, Canvas and HTML, offering the most expressive control over visualizations.

D

DevDocs

Free

Hundreds of API docs in one place, offline and fast to search

T

three.js

Free

The JavaScript library for rendering 3D graphics in the browser, standard for interactive web work.

C

Carbon

Free

Turn source code into beautiful images to share

R

ray.so

Free

Turn code and screenshots into clean card images

R

Reqres

Free

Hosted fake REST API that returns real responses

G

Godot Engine

Free

An open-source 2D and 3D game engine that can be used commercially with no royalties.

R

Rust

Free

The source repository for Rust, the systems language that enforces memory safety at compile time.

H

httpbin

Free

Request-testing server for trying out HTTP methods, headers and status codes

M

Mockaroo

Free

Generate realistic fake data in bulk from a schema (CSV/JSON/SQL)

E

ExplainShell

Free

Break down long shell commands option by option

I

iHateRegex

Free

Library of common regular expressions like email, phone and IP, plus a playground

D

Diffchecker

Freemium

Compare differences in text, images, PDFs and folders

J

JSONLint

Free

Validate, format and locate errors in JSON

J

JSON Hero

Free

Viewer that explores huge JSON with automatic type detection

T

Transform

Free

Convert between JSON, TS, Go, Rust, Zod and 25+ formats

C

crt.sh

Free

Search Certificate Transparency logs for every SSL certificate issued to a domain

C

ChartDB

Freemium

Visualize your existing database schema as an ER diagram with a single query

S

ShellCheck

Free

Online linter that catches bugs and anti-patterns in shell scripts

N

npm trends

Free

Compare download trends of npm packages on a graph

B

Base64 Decode

Free

Base64 encode and decode with support for files and multiple languages

R

RapidTables

Free

Vast collection of online reference tables and calculators for number bases, units, color and math

U

UUID Generator

Free

Instantly generate UUIDs of various versions in bulk

D

DB Fiddle

Free

Test and share SQL for MySQL, PostgreSQL and more online

P

Programiz

Free

Run and learn 20+ languages in the browser with no install

R

RegExr

Free

Regular expression visualizer with cheatsheet and community patterns, great for learning

T

Text Compare!

Free

No-signup text diff plus utilities like lowercasing and sorting

M

Mergely

Free

Pure-JS diff to compare and merge two documents or code side by side

E

Epoch Converter

Free

Convert Unix timestamps to dates and back, with examples in 20+ languages

C

Crontab.guru

Free

Translate cron expressions into plain English and next run times in real time

Z

zrok

Free

Tunnel and share local apps securely with zero-trust, open-source networking

S

SQLNoir

Freemium

Crack noir detective cases by investigating databases with SQL

B

Bundlephobia

Free

Check the bundle size, dependencies and download time of npm packages

S

SQLite Online

Free

Query SQLite and PostgreSQL right in the browser

C

Compiler Explorer

Free

Compare in real time what assembly your source compiles to

S

StackBlitz

Freemium

Full-stack IDE that runs in the browser (WebContainers)

R

Regex101

Free

Regular expression tester with real-time matching, explanation and a debugger

C

Can I use

Free

Tables of web feature support and usage share by browser

Q

QuickRef.ME

Free

Searchable (⌘K) quick-reference cards for developers

B

Beeceptor

Free

Spin up mock REST/GraphQL/gRPC servers instantly without a backend

J

JSON Crack

Free

Visualize JSON/YAML/CSV/XML as interactive graphs

R

Regexper

Free

Visualize regular expressions as railroad diagrams (SVG/PNG)

W

Wandbox

Free

Sandbox to instantly run and share code across multiple C++ compiler versions and more