Free online developer tools

207 tools

Small utilities developers reach for daily: JSON and YAML formatters, Base64 and URL encoders, regex testers, JWT decoders, diff viewers and cron helpers. Prefer tools marked as running in your browser when you paste tokens, keys or production data, because nothing is uploaded.

Showing 73–96 of 207

0.741score
Web Serial Terminal
Google Chrome Labs
Talks to serial devices such as Arduinos from the browser using the Web Serial API.
ArtifactNo sign-up★ 315developer tools
0.737score
SwiftFiddle
SwiftFiddle
Run and share Swift snippets in the browser.
ArtifactNo sign-up★ 275developer tools
0.731score
AsyncAPI Studio
AsyncAPI Initiative
Validates AsyncAPI documents, previews the docs and generates templates.
ArtifactNo sign-up★ 213developer tools
0.729score
Float Toy
Evan Wallace
Interactive IEEE 754 float editor where you flip sign, exponent and mantissa bits and see the value.
ArtifactNo sign-up★ 199developer tools
0.729score
Swagger Toolbox
essuraj
Generates Swagger schema models in YAML or JSON from a sample of JSON data.
Artifact★ 261developer tools
0.728score
OCaml Playground
OCaml org
Runs OCaml in a browser toplevel with no installation.
ArtifactNo sign-up★ 193developer tools
0.726score
Decomposerize
Composerize
Converts a docker-compose file back into docker run commands.
ArtifactNo sign-up★ 172developer tools
0.721score
Tasmota Web Installer
Tasmota
Installs Tasmota firmware on ESP devices from the browser.
ArtifactNo sign-up★ 145developer tools
0.712score
First Follow
MikeDevice
Generates FIRST, FOLLOW and PREDICT sets for a grammar, to help when designing a programming language.
Artifact★ 130developer tools
0.708score
Json Formatter Live
alexandrunastase
Keyboard-driven JSON formatter and editor that works privately in the browser and can be installed as a web app.
Artifact★ 114developer tools
0.706score
Npm Unpkg
uiwjs
Browse the files inside any npm package in the browser, built on unpkg.
Artifact★ 103developer tools
0.701score
Log Voyager
hsr88
Opens and analyzes very large log files, over 10 GB, directly in the browser without uploading them.
Artifact★ 121developer tools
0.684score
JSONPlaceholder
typicode
Free fake REST API with posts, comments, todos and users supporting all HTTP methods.
ArtifactNo sign-up★ 5.3Kdeveloper tools
0.678score
Omatsuri
rtivital
A web app with 12 open-source tools for frontend work, such as SVG and CSS utilities.
Artifact★ 3Kdeveloper tools
0.629score
Tools
mydearcc
A toolbox of free online utilities including CSS minify, JSON format, encryption, QR codes and image tools.
Artifact★ 376developer tools
0.622score
Tools
jaywcjlove
A collection of online utilities for web developers and programmers, hosted as one tool site.
Artifact★ 274developer tools
0.622score
Html Tools
justhtmls
An open-source set of lightweight HTML tools that run in the browser with no install and keep data private.
Artifact★ 268developer tools
0.611score
Html Tools
chicogong
A toolbox of over 1,000 single-file HTML tools that run in the browser, work offline and keep data local.
Artifact★ 161developer tools
0.608score
It Toolbox
Zoroaaa
Online developer toolbox with 146 tools for formatting, encoding, hashing, network lookups, text processing and colors.
Artifact★ 142developer tools
0.606score
Text Forge
seehiong
Toolbox with text processing, code formatting, regex testing, encoding, hashing and other web utilities.
Artifact★ 129developer tools
0.606score
GraphiQL Online
Lucas Constantino
Hosted GraphiQL that connects to any GraphQL endpoint URL you supply.
ArtifactNo sign-up★ 70developer tools
0.603score
JMESPath
JMESPath
Try JMESPath expressions against JSON in an interactive tutorial and tester.
ArtifactNo sign-up★ 62developer tools
0.596score
Nano ID Collision Calculator
zelark
Estimates collision odds for Nano ID given alphabet size, id length and generation speed.
ArtifactNo sign-up★ 44developer tools
0.593score
Json Viewer
uiwjs
Paste JSON to beautify it, pretty print it and explore it as a collapsible tree.
Artifact★ 60developer tools