🛠 28 Free Dev Tools · No Signup · Privacy-First

Free Developer Tools

Practical utilities for your daily workflow. No signup, no tracking, no ads. Your data never leaves your browser.

✓ 100% Free ✓ No Account Required ✓ Works Offline ✓ Your Data Stays Private
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Team Timezone Converter

Distributed Teams · Scheduling

Add your team's cities. Pick a meeting time. See every teammate's local time side-by-side — DST-aware, next-day-aware, and honest about who has to take the call at midnight. Team overlap heatmap included.

DST-aware 30+ common cities Overlap heatmap Browser-only
Open converter →
$_

Curl Command Builder

HTTP · API Development

Build any HTTP request visually — method, URL, headers, query params, body, auth. Get equivalent curl, JavaScript fetch, and Python requests code side-by-side. Everything runs in your browser.

curl + fetch + Python Bearer & Basic auth Auto JSON format Browser-only
Open builder →
Most Popular { }

JSON Formatter & Validator

Data · API Development

Paste messy JSON, get it beautifully formatted and validated instantly. Syntax highlighting, error detection, tree view, and path copying. The fastest JSON tool on the web.

Format & validate Syntax highlighting Tree view Copy paths
Open formatter →
{ + }

JSON Diff Viewer

Data · API Debugging

Paste two JSON payloads, get a colour-coded deep diff — added, removed, and changed keys at every level of nesting. Perfect for API-response debugging, config comparison, and schema-change review.

Deep recursive diff Array-order toggle Case-insensitive mode Browser-only
Open diff viewer →
{ }→TS

JSON to TypeScript Converter

TypeScript · Type Generation

Paste any JSON, get clean TypeScript interfaces or types — with nested objects, optional fields, union inference, and sensible naming. No signup, runs entirely in your browser.

Nested objects Array merge Optional fields Browser-only
Open converter →
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Blameless Postmortem Generator

SRE · Incident Reports

Fill in incident details, get a full blameless incident report in Markdown — summary, timeline, root cause, contributing factors, action items. Copy or download .md.

Live preview Blameless-by-design Markdown output Browser-only
Open generator →
pkg→MD

README.md Generator

Markdown · package.json

Paste a package.json, instantly get a polished GitHub-flavored README — with badges, npm/yarn/pnpm/bun install commands, scripts table, and contributing sections. Live preview included.

All 4 package managers Shields.io badges Live preview Browser-only
Open generator →

Cron Expression Builder

DevOps · Scheduling

Build cron expressions visually with plain English descriptions. See the next 5 run times instantly. Never get cron syntax wrong again.

Visual builder Plain English Next run times Copy & paste
Open builder →
SQL

SQL Formatter

SQL · Beautifier

Paste any SQL — SELECT, CTEs, subqueries, window functions — and get clean, indented, readable output instantly. Works with Postgres, MySQL, SQL Server, SQLite, BigQuery.

Runs offline All dialects Configurable Copy output
Open formatter →
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CSS clamp() Calculator

CSS · Fluid Typography

Generate the exact clamp() value for fluid type and responsive spacing. Live preview at every viewport width, copyable CSS, supports both rem and px.

Live preview rem & px Presets Copy CSS
Open calculator →
UUID

UUID Generator & Decoder

Identifiers · v4 / v7

Generate UUID v4 (random) or UUID v7 (sortable, timestamp-based) in bulk, and decode any UUID to extract version, variant, and embedded timestamp. Crypto-secure, browser-only.

v4 & v7 Bulk generate Decode timestamp Browser-only
Open generator →
๐ŸŽฒ

Stand-up Question Generator

Team Rituals · 120+ Questions

120+ curated questions across five categories — daily standup, retrospective, team culture, technical check-in, and async warm-up. Copy in one click.

5 categories Rotate weekly One-click copy Browser-only
Open generator →
/.*/

Regex Tester & Explainer

Text · Pattern Matching

Write and test regular expressions with live matching, capture group highlighting, and plain English explanations of what your pattern does.

Live matching Capture groups Explanations Common patterns
Open tester →
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CIDR Subnet Calculator

Networking · IPv4

Enter any IPv4 CIDR block and get the network address, broadcast, usable host range, subnet mask, wildcard, and binary breakdown. Works offline in your browser.

Network & broadcast Host range Binary view RFC 1918 check
Open calculator →
⚖️

Tech Stack Comparison

Architecture · Decision Making

Compare frameworks and libraries side by side — community size, performance, learning curve, and ecosystem. Make informed tech decisions.

Side by side npm downloads GitHub stars Pros & cons
Compare stacks →
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Release Notes Generator

DevOps · Documentation

Create beautiful, structured release notes in seconds. Paste your git log or add entries manually — get formatted output in Markdown, HTML, or Keep a Changelog format.

Auto-categorize 4 formats Git log parser Auto-saves
Generate notes →
๐Ÿ”ข

Semantic Version Calculator

Versioning · Release Management

Bump versions correctly, compare two versions side by side, and validate version strings against the semver spec. Never get MAJOR.MINOR.PATCH wrong again.

Version bump Compare Validate Pre-release tags
Calculate version →
git

Git Command Finder

Version Control · Search

Type what you want to do in plain English — "undo my last commit", "rename a branch", "delete remote branch" — and get the exact command, an explanation, and the caveats that'll save you.

70+ scenarios Plain English Risk-flagged One-click copy
Open finder →
418

HTTP Status Code Lookup

Backend · APIs

Search every HTTP status code — from 100 to 599 plus Cloudflare and WebDAV extensions. For each: what it means, when to return it, common causes when you see it in logs, and a real-world example.

60+ codes Live search Real examples Copy-ready
Open lookup →
429

API Rate Limit Calculator

Backend · APIs

Convert RPS ↔ RPM ↔ RPH ↔ RPD, model token-bucket bursts, plan exponential-backoff retries, and size concurrency with Little's Law. Four calculators in one tool.

Rate convert Token bucket Backoff Browser-only
Open calculator →

Code Review Checklist Generator

Process · PRs

Generate a focused review checklist by language (TS, Python, Go, Rust, Java, C#, SQL) and PR type (feature, bugfix, refactor, security, performance, dependency). Copy as Markdown straight into your PR.

9 languages 6 PR types Markdown export Browser-only
Open generator →
UTC

Unix Timestamp Converter

Time · Debugging

Paste any timestamp (seconds, milliseconds, microseconds, or ISO 8601) — get every other format back, in any IANA timezone. Live UTC clock, one-click copy, common offsets (+1 day, -7 days, ±1 year), and a 2038 overflow reminder.

Auto-detect unit IANA timezones Relative time Browser-only
Open converter →
JWT

JWT Decoder & Inspector

Auth · Security

Paste any JSON Web Token to instantly decode header and payload, see every claim, get a human-readable expiry status, and catch common security warnings (alg=none, missing exp, long-lived tokens).

Header + payload Expiry check Security warnings Browser-only
Open decoder →
%20

URL Encoder & Decoder

URLs · Percent Encoding

Encode and decode URLs the right way. Toggle between encodeURIComponent, encodeURI, and form-style + encoding — and see a per-character diff of exactly what changed. Runs entirely in your browser.

3 encoding modes Per-character diff Unicode-safe Browser-only
Open encoder →
feat:

Conventional Commit Builder

Git · Release Workflow

Build a Conventional Commits 1.0-compliant message visually. Pick type, scope, breaking-change flag, body, and footers — with live validation, syntax-colored preview, and one-click copy. Eight real-world examples included.

11 commit types Live validation Breaking-change toggle Browser-only
Open builder →
O(n)

Big O Cheat Sheet & Calculator

Algorithms · Reference

Pick an algorithm or data structure and see its time/space complexity, when to use it, and a rough operation-count estimate for your input size. Includes full reference tables for common sorts and data-structure operations.

20+ algorithms Operation estimator Wall-clock estimate Browser-only
Open cheat sheet →
µ/M

Microservice vs Monolith Decision

Architecture · Decision

Answer 10 questions about your team, scale, deploy cadence, ops maturity, and data shape. Get an opinionated recommendation — monolith, modular monolith, or microservices — with reasoning, trade-offs, and a one-paragraph defense you can take to your team.

10-question quiz Reasoning + trade-offs Copyable defense paragraph Browser-only
Open decision tool →
2×2

Tech Debt Prioritizer

Planning · Engineering Leadership

Score each piece of tech debt on impact and effort. Get an interactive 2×2 quadrant matrix (Quick Wins, Big Bets, Fill-ins, Avoid) and an ROI-ranked backlog you can take to quarterly planning. Saves to your browser; exports to Markdown, JSON, or CSV.

Impact × effort matrix ROI ranking Export to Markdown / JSON / CSV Browser-only
Open prioritizer →

Why we built developer tools

We're a team of engineers who got tired of ad-heavy, signup-required tools that track everything you paste. These tools run entirely in your browser — your JSON, regex, and code never touch a server.

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Privacy First

Your data stays in your browser. No server calls, no logging, no analytics on what you paste. We literally can't see your input.

No Dark Patterns

No signup walls, no premium upsells, no "you've reached your limit" banners. Every feature is free, every time.

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Built for Speed

Instant results, no loading spinners, no waiting for server responses. Everything runs client-side for zero-latency feedback.

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