DevDeck — every little dev tool, in one friendly place

Name: DevDeck
Author: ezin-rev

75 free developer tools that run in your browser: convert, encode, format, validate and generate.

Power tools

Smart Paste — Paste anything — it figures out what it is and shows you the answer
Tool Chain — Link tools together, e.g. Base64 decode → format JSON, all in one go

Json <> Yaml Converter — Convert Json data to Yaml and vice versa
Number Base Converter — Convert numbers from one base to another
Date & Timestamp Converter — Turn Unix timestamps into readable dates and back, in any time zone
Color Converter — Pick a colour and get HEX, RGB and HSL, plus a contrast check
CSV <> JSON Converter — Turn spreadsheet data into JSON and back, with a table preview
Cron Schedule Explainer — See what a cron schedule means in plain words, and when it runs next
TOML Converter — Turn TOML into JSON or YAML and back
File Permission Calculator — Tick boxes to get chmod numbers like 755, or read what they mean
.env Converter — Turn a .env file into JSON, YAML, a Kubernetes Secret or ConfigMap, docker -e flags and more
docker run → Compose — Turn a long docker run command into a tidy compose.yaml
curl to Code — Turn a curl command into JavaScript, Python, HTTPie or PowerShell

HTML Encoder / Decoder — Encode or decode all the applicable characters to their corresponding HTML entities
URL Encoder / Decoder — Encode or decode all the applicable characters to their corresponding URL entities
Base 64 Encoder / Decoder — Encode and decode Base64 data
JWT Encoder / Decoder — Decode, verify and create signed JWTs (HS, RS, PS and ES algorithms)
QR Code Generator — Make a QR code for a link, text or Wi-Fi login, and download it
QR Code Reader — Read a QR code from a picture, a pasted screenshot or your camera
GZIP Compressor / Decompressor — Compress text or files with gzip/deflate, or unpack them
URL Parser & Builder — Break a web address into parts and edit its parameters
Image <> Base64 — Turn an image into a data address for code, or preview one
String Escaper — Escape text safely for JSON, JavaScript, SQL, regex, shell and CSV

JSON Formatter — Indent or minify JSON data
SQL Formatter — Tidy up database queries for PostgreSQL, MySQL, SQL Server and more
XML Formatter — Indent or minify XML and spot mistakes
NGINX Config Formatter — Tidy nginx.conf indentation and spot missing ; and }
Markdown Preview — Write Markdown and see the formatted result side by side

Hash / Checksum Generator — MD5, SHA-1, SHA-256, SHA-512 and CRC32 of text or files, and compare checksums
UUID Generator — Generate UUIDs version 1 and 4
Password Generator — Make strong passwords or easy-to-remember passphrases
ULID Generator — Make sortable ULIDs and read the time inside one
RSA Key Generator — Make RSA key pairs as PEM, PKCS#1, JWK or OpenSSH
SSH Key Generator — Make Ed25519, ECDSA or RSA SSH keys in OpenSSH format, and check fingerprints
Certificate & CSR Generator — Make a self-signed certificate, a signing request (CSR) or your own CA, with its private key
Kubernetes Manifest Generator — Fill in a form, get a Deployment, Service and Ingress ready to apply
Randomizer — Random numbers, pick or shuffle from a list, split into groups, dice and coin flips
Lorem Ipsum Generator — Placeholder text for designs, in paragraphs, sentences or words
Fake Data Generator — Realistic test people as JSON, CSV or SQL — never real data

SSL/TLS Certificate Decoder — Read a certificate, chain or CSR: who it’s for, expiry, fingerprints, chain check and key match
Docker Compose Validator — Find typos, port clashes, missing volumes and risky settings in a compose.yaml
Kubernetes YAML Validator — Check manifests for removed APIs, selector mismatches, bad names, missing resources and more
Kubeconfig Inspector — See contexts, clusters and logins, certificate expiry, and copy it without secrets
Docker Image Inspector — Break down an image name and read docker inspect output: user, ports, env, layers

CIDR & Subnet Calculator — Network, mask, host range and subnets for any IP range, plus an “is this IP inside?” check
Sizes, Durations & Transfer Time — Mi vs MB, 1h30m in seconds, and how long a download takes
Uptime & SLA Calculator — What 99.9% really allows in downtime, and the uptime of a whole chain of services
Version Range Checker — Check which versions match ^1.4.0, ~2.1 or >=1 <2, compare and sort versions

Text Analyzer & Utilities — Count words and characters, change case, sort, dedupe, trim and clean up text
Text Comparer — Compare two texts and highlight the differences
List Comparer — Two lists: what’s only in one, in both, or in either
Duplicate Detector — Find repeated lines and values, with counts, and remove them
Text Delimiter — Turn a list into comma-separated text, ('a','b') for SQL, a JSON array and more
RESX Translator — Translate .NET .resx resource files side by side and export the translated file
Regex Tester — Try a search pattern and see every match highlighted live

JSONPath Tester — Try JSONPath queries on JSON or YAML and see every match
YAML to JSONPath — List every value in YAML/JSON with its path — JSONPath, dot notation or helm --set
JSON Schema Generator & Validator — Make a schema from example JSON, or check JSON against a schema
JSON to C#, PHP, TypeScript, Go… — Turn JSON into C# classes, PHP arrays or classes, TypeScript, Go, Python or Java
YAML & Helm Values Diff — Compare two YAML/JSON files key by key — and get just the overrides or helm --set flags
XML / XSD Validator — Check XML is well-formed and matches an XSD schema
XSD Generator — Make an XSD schema from a sample XML file

HTTP Request Builder — Send GET/POST/PUT… requests with headers and a body, and see the response
WebSocket Client — Connect to a WebSocket, send messages and watch replies live
DNS Lookup — A, AAAA, MX, TXT, NS, CAA and more for any domain, plus an email setup check
Port Checker & Port List — Quick check whether a web port answers, commands for a real check, and common ports
gRPC Helper — Build grpcurl commands and decode raw protobuf messages

Image Converter — Convert between PNG, JPEG, WebP, AVIF and BMP, resize, rotate and flip
PNG Compressor — Shrink PNGs by reducing colours, keeping transparency
Color Blind Simulator — See an image or colour palette the way people with colour blindness do
File Splitter & Joiner — Split text or big files into pieces, and join pieces back together

HTTP Status Codes — What 404, 500 and friends mean, in plain words
Keyboard Event Inspector — Press any key to see its key, code and keyCode for your scripts

Slugify — Turn titles into clean web-address slugs like my-first-post
Unicode Inspector — See every character’s code point, UTF-8 bytes and escapes — find hidden spaces and look-alikes