{ }DevToolsDaily

Tools Interview Prep

Cheatsheets Directory My space Blog

Ctrl + K

All Developer Tools

A complete directory of all developer tools, tutorials, cheatsheets, and articles available on DevTools Daily.

Tool Collections

Image & Screenshot Tools

XML Tools

Security Tools

DevOps Tools

HTTP & API Tools

SEO Tools

Local Data Tools

Log & Privacy Tools

Formatters

CSS Formatter

HTML Formatter

Javascript Formatter

JSON Formatter

XML Formatter

XML Validator

XML Viewer

XML Editor

SQL Formatter

Inline SQL variables

Stack Trace Formatter

Java Exception Formatter

How to

Random numbers in javascript

Random numbers in python

Random numbers in Java

Run MySQL in Docker

Run Postgres in Docker

Playgrounds

Graphviz Online Editor

OpenSCAD Playground

OpenSCAD Examples

OpenSCAD Tools

Three.js Playground

Three.js Examples

JQ Playground

JsonPath Playground

Markdown Editor

Regex Tester

Python Regex Tester

JavaScript Regex Tester

Go Regex Tester

Java Regex Tester

XPATH Tester

Fake JSON API

GraphQL Playground

DevTools Chat

SQL Playground

DuckDB Playground

MCP Inspector

Parquet Viewer

SQL Examples

Python Playground

Python Examples

Javascript Playground

JavaScript Examples

Go Playground

Go Examples

Rust Playground

Rust Examples

Java Playground

Java Examples

C++ Playground

Ruby Playground

Lua Playground

MermaidJS Playground

PlantUML Playground

PlantUML Examples

Graphviz to Mermaid Converter

Excalidraw Online Editor

Excalidraw Examples

Excalidraw System Architecture Example

Excalidraw User Flow Example

Excalidraw Mobile Wireframe Example

UUID / GUID Generator

HTML5 Canvas Playground

Logo Turtle Graphics Playground

JSCAD Playground

GLSL Shader Playground

p5.js Sketch Playground

Blockly Playground

L-system Generator

Live-code Audio Playground

Random text generator - lorem ipsum

Random JSON generator

SVG Preview & Editor

Color Picker

Color Contrast & Converter

HEX ↔ RGB Converter

Color Palette Generator

CSS Box Shadow Generator

HTML Entities

Changelog

Compare timezones

List of cities and timezones

TODO List

Kanban Board

Mind Map Maker

Keyboard Event Viewer

Date and time

Stopwatch

Timer

Countries

Cron Expression Generator & Builder

Security

JWT Decoder & Debugger

Hash & Checksum Generator

HMAC Generator & Verifier

Password Generator

Developer Secret & Token Generator

Secret Detector & Redactor

X.509 Certificate Viewer

HTTP Security Header Helper

SEO

SEO Inspector

JSON-LD Inspector

Social Preview Inspector

Text Tools

Text Toolbox

Generators

QR Code Generator

Mock Data Generator

ULID Generator & Decoder

Code Screenshot Generator

Social Post Screenshot Generator

Messaging Screenshot Generator

AI Chat Screenshot Generator

App Store Screenshot Generator

Image Tools

Image Toolkit

Developer Meme Generator

DevOps

.gitignore Generator

.env Toolkit

Dockerfile & Compose Generator

GitHub Actions Workflow Explainer

CIDR / Subnet Calculator

Log & Privacy

Log and Privacy Workbench

Data Tools

Data Explorer

Recipes

Developer Recipes

Pipelines

Tool Pipelines

HTTP Tools

API Workbench

Cheatsheets

Docker Cheatsheet

Docker Compose Cheatsheet

Crontab Cheatsheet

Graphviz Cheatsheet

JQ Cheatsheet

CSS Cheatsheet

HTML5 Canvas Cheatsheet

ffmpeg Cheatsheet

Go Cheatsheet

GraphQL Cheatsheet

Java Cheatsheet

JavaPoet Cheatsheet

Markdown Cheatsheet

MermaidJS Cheatsheet

PlantUML Cheatsheet

SQL Cheatsheet

SQLite Cheatsheet

MySQL Cheatsheet

PostgreSQL Cheatsheet

XML Cheatsheet

YAML Cheatsheet

Regex Cheatsheet

XPath Cheatsheet

JsonPath Cheatsheet

awk Cheatsheet

Bash scripting Cheatsheet

chmod & chown Cheatsheet

curl Cheatsheet

du Cheatsheet

find Cheatsheet

grep Cheatsheet

GNU Screen Cheatsheet

sed Cheatsheet

ssh Cheatsheet

tmux Cheatsheet

Cargo (Rust) Cheatsheet

Git Cheatsheet

Tar Cheatsheet

Zip Cheatsheet

Unzip Cheatsheet

Java String.format Cheatsheet

Find Listening Ports Cheatsheet

kubectl Cheatsheet

Python Cheatsheet

Rust Cheatsheet

Vim Cheatsheet

PowerShell Cheatsheet

Redis Cheatsheet

Nginx Cheatsheet

OpenSSL Cheatsheet

OpenSCAD Cheatsheet

k6 Cheatsheet

Lua Cheatsheet

Http Codes

Everything about JSON

unicode

AI emojis

unicode flags

ASCII

ASCII Art Tools

ASCII Character Reference

ASCII Drawing Tool

Box Drawing ASCII

Code Comment ASCII Art

Text to ASCII Art

Image to ASCII Art

ASCII tree

Tutorials

All Tutorials

JQ Tutorial

JsonPath Tutorial

Regex Tutorial

Graphviz Tutorial

SQL Interactive tutorial

Python Tutorial

How to

How to concatenate 2 fields in JSON using JQ

How to create Sequence diagram in MermaidJS

How to create Flowchart diagram in MermaidJS

How to create Class diagram in MermaidJS

How to create ER diagram in MermaidJS

How to create State diagram in MermaidJS

How to create Gantt chart in MermaidJS

How to create a Git graph diagram in MermaidJS

How to create a Sequence diagram in PlantUML

How to create a Class diagram in PlantUML

How to create an Activity diagram in PlantUML

How to create a Use Case diagram in PlantUML

How to use Regex in JQ

Overview

Your One-Stop Shop for All Things JQ

Everything about JSON

Everything about Markdown

Everything about Regex

Mermaid Diagrams

HTML5 canvas - Drawing made easy

Everything about SQL

Everything about Sqlite

Everything about DuckDB

Everything about Parquet

Everything about UUID

Everything about LangChain

Online Playgrounds

Everything about Go

Everything about Rust

Everything about Java

Articles

Building a Real MCP Server: A QR Code Generator Example

Buzz Coding Agents, Part 3: A Ticket System for the Agent Army

Buzz Coding Agents, Part 2: Adding Agents on a Homelab

Why We Reverted Our Firestore Offline Migration

Storing 2M Analytics Events: From Heavy JSON to Parquet & DuckDB

A week with Buzz: coding agents in a group chat

Moving DevTools Daily's backend from Azure to a $10 VPS

Announcing Our Interview Prep Platform: A Free LeetCode & NeetCode Alternative

How to Decode and Verify a JWT Safely

HMAC-SHA256 Explained with Node.js and Python Examples

HTTP Security Headers Checklist with Secure Examples

How to Redact Production Logs Before Sharing Them

Cron Expression Examples: Daily, Weekdays, Intervals and Leap Days

How to Compare Development and Production .env Files

Convert cURL to Fetch, Axios, Python, Go and Java

How to Debug CORS and Browser API Requests

Profile CSV and JSON Data Without Uploading It

GitHub Actions Security: Permissions and SHA Pinning

Building an OG Image Generator with GitHub Copilot

Save Figma site as static HTML

JQ - Handling null values and default values

Sending emails with Azure - Part 3

Sending emails with Azure - Part 2

Sending emails with Azure

Elevate your code comments with ASCII Art - 5 tips

Building gradle dependency graph using Python and GraphViz

How to use json path for json manipulations

Building a Lightweight Random JSON Generator with a Custom Vocabulary

Integrating MermaidJS with ReactJS Hooks

Graphviz layout options

Unveiling the Mock GraphQL Tool

Query and Transform JSON data with JQ

Generating MermaidJS Flow Chart Diagrams Programmatically in JavaScript

Using CodeMirror in Gatsby

New AI-powered DevTools

Advanced JQ Patterns

Using Graphviz JS in Gatsby to preview DOT

Understand the Basics of SQL Joins with Examples

Building File tree view in React and Electron

Switching from Direct calls to OpenAI to Langchain

Contact Form in Gatsby JS and Firebase realtime database

Real examples of Graphviz

ChatGPT API using python SDK example

Use react hooks to load third party library from CDN

Generating Random Text with JavaScript

Generate short UUID

Showing inline errors in codemirror

Building MermaidJS Markup programmatically in Python

Directory

All categories

Browse by category

API Development & Integrations

AI Coding & Agents

MCP Servers

Agent Skills & Tooling

Databases & Data Tools

Hosting & Deployment

DevOps & Infrastructure

Observability & Monitoring

Authentication & Identity

Application Security

Testing & QA

Diagrams & Design

Linters & Formatters

Terminal & Productivity

Converters & Online Utilities

Local Dev & Scaffolding

Interview & Learning

Get listed

Submit a tool

Editorial policy

GraphViz examples

GraphViz examples

Graphviz example: System Design Graphviz Example

Graphviz example: Entity Relationship Diagram Graphviz Example

Graphviz example: Workflow Diagram Graphviz Example

Graphviz example: BPMN or Business process diagram Graphviz Example

Graphviz example: Services interaction diagram Graphviz Example

Graphviz example: Database ERD Graphviz Example

Graphviz example: Family Tree Graphviz Example

Graphviz example: Subgraphs Graphviz Example

Graphviz example: Decision Tree Graphviz Example

MermaidJS examples

MermaidJS examples

MermaidJS example: System Design Diagram

MermaidJS example: Entity Relationship Diagram

MermaidJS example: Workflow Diagram

MermaidJS example: Simple Sequence Diagram

MermaidJS example: Pie Diagram

MermaidJS example: Class Diagram

MermaidJS example: State Diagram

MermaidJS example: Gantt Chart

Coding Questions

All Coding Problems

My Progress

All Coding Solutions

Coding Mock Interview

Speak Out Loud Practice

Quick practice

Learn

Learning Paths

Two Sum

Merge Intervals

Reverse a String

Longest Common Prefix

Palindrome String

Palindromic Substrings

Longest Palindromic Substring

Palindrome Linked List

Roman to Integer

Letter Combinations of a Phone Number

Valid Parentheses

Find the Index of the First Occurrence in a String

Length of Last Word

Spiral Matrix

FizzBuzz

Contains Duplicate

Maximum Subarray

Fibonacci Number

Factorial

Move Zeroes

Single Number

Best Time to Buy and Sell Stock

Valid Anagram

Binary Search

Count Vowels

Climbing Stairs

Product of Array Except Self

Trapping Rain Water

Edit Distance

Median of Two Sorted Arrays

Longest Valid Parentheses

Palindrome Number

Plus One

Majority Element

Is Subsequence

First Unique Character in a String

Search Insert Position

House Robber

Jump Game

Coin Change

Longest Substring Without Repeating Characters

Container With Most Water

Number of Islands

Word Break

Longest Increasing Subsequence

Largest Rectangle in Histogram

Sliding Window Maximum

Jump Game II

Reverse Linked List

Maximum Depth of Binary Tree

Course Schedule

Rotting Oranges

Redundant Connection

Kth Largest Element in an Array

Top K Frequent Elements

Subsets

Invert Binary Tree

Same Tree

Validate Binary Search Tree

Binary Tree Level Order Traversal

Lowest Common Ancestor of a BST

Merge Two Sorted Lists

Linked List Cycle

Reorder List

Clone Graph

Pacific Atlantic Water Flow

Network Delay Time

Merge K Sorted Lists

Find Median from Data Stream

Permutations

Combination Sum

Word Search

Implement Trie

Design Add and Search Words

LRU Cache

Unique Paths

Pascal's Triangle

Count Primes

Sqrt(x)

Happy Number

Excel Sheet Column Number

Insert Interval

Non-overlapping Intervals

Sort Colors

Number of Provinces

Minimum Size Subarray Sum

3Sum

Rotate Image

Search in Rotated Sorted Array

Longest Consecutive Sequence

Sum of Two Integers

Symmetric Tree

Diameter of Binary Tree

Kth Smallest Element in a BST

Add Two Numbers

Remove Nth Node From End of List

Path Sum

Convert Sorted Array to Binary Search Tree

Reverse Linked List II

Swap Nodes in Pairs

Binary Tree Right Side View

Merge Two Binary Trees

Path Sum II

Construct Binary Tree from Preorder & Inorder

Linked List Cycle II

Odd Even Linked List

Task Scheduler

Connected Components in an Undirected Graph

Palindrome Partitioning

Word Search II

Word Ladder

Daily Temperatures

Decode Ways

Gas Station

Alien Dictionary

Binary Tree Maximum Path Sum

Meeting Rooms II

Minimum Window Substring

Longest Increasing Path in a Matrix

Range Sum Query - Mutable

Cheapest Flights Within K Stops

Group Anagrams

Min Stack

Accounts Merge

K Closest Points to Origin

Counting Bits

Maximum Product Subarray

Course Schedule II

Kth Smallest Element in a Sorted Matrix

Missing Number

Find All Anagrams in a String

Find Minimum in Rotated Sorted Array

Search a 2D Matrix

Single Number II

Subarray Sum Equals K

Isomorphic Strings

Next Permutation

First Missing Positive

Set Matrix Zeroes

Spiral Matrix II

Balanced Binary Tree

Lowest Common Ancestor of a Binary Tree

Binary Tree Zigzag Level Order Traversal

Pseudo-Palindromic Paths in a Binary Tree

N-Queens

Rotate String

Min Cost Climbing Stairs

House Robber II

Unique Paths II

Partition Equal Subset Sum

House Robber III

Generate Parentheses

Longest Common Subsequence

Flatten Binary Tree to Linked List

01 Matrix

Find the Duplicate Number

Merge Sorted Array

Top K Frequent Words

Path Sum III

Combination Sum III

Sort List

Binary Tree Inorder Traversal

3Sum Closest

Combination Sum II

Decode String

Maximal Square

Binary Tree Preorder Traversal

Binary Tree Postorder Traversal

Valid Sudoku

Find All Duplicates in an Array

Reverse Words in a String

Two Sum II - Input Array Is Sorted

Koko Eating Bananas

Integer to Roman

Reverse Integer

H-Index

System Design

System Design Questions

System Design Solutions

Design a URL Shortener

Design a Rate Limiter

Design Twitter

PrivacyTermsFAQChangelogFeature RequestsBlogAll ToolsPricingContact Us © Monkey SkatesHave kids?