Every tool you need to work with code, in one place
112 free developer utilities at your fingertips. Formats, crypto, HTTP, text, SQL, dummy data, images and more — 100% in the browser. Nothing is uploaded.
Store screenshots without a designer
Pick a themed template set, drop in raw screenshots, then edit everything directly on the canvas — drag text and devices into place, rewrite headlines inline, and export exact App Store and Play Store sizes. 100% in your browser.
- Themed template sets — a full 5-slide store gallery in one click
- Drag headlines, badges, and devices right on the canvas
- Double-click any text to edit it in place
- Procedural iOS & Android frames — Dynamic Island, punch-hole, clay
- Exact Play Store & App Store sizes, exported as PNG/JPEG/WebP or ZIP
The most advanced app icon generator on the web
Upload a logo, tune padding and background, add promo badges, preview on iOS and Android mockups, then download a ZIP with AppIcon.appiconset, Android mipmap layers, store marketing frames, and web/PWA sizes. Nothing is uploaded. Go beyond single PNG exports — design in a full-page studio with device previews, promo badges, marketing frames, and multi-app batch export.
- Full Xcode AppIcon.appiconset + Android adaptive layers
- Live iPhone & Pixel mockups with store listing previews
- Promo badges — Sale, holidays, seasonal overlays
- Store marketing frames & batch white-label variants
- 100% in-browser — your logo never leaves the tab
Start with these
All toolsJSON Formatter
Beautify, minify, sort, and validate JSON entirely in the browser.
JSON → TS
Infer TypeScript interfaces, type aliases, or Zod schemas from sample JSON.
JWT Debugger
Decode JWT header, payload, and signature in-browser with expiry countdown.
cURL → Code
Paste a cURL command and get Go net/http, Python requests, fetch, and Axios.
Regex Tester
Test JavaScript regular expressions with matches, groups, flags, and replace.
UUID Generator
Bulk-generate UUID v4, UUID v7, NanoID, and high-entropy API keys locally.
SQL Formatter
Pretty-print SQL for PostgreSQL, MySQL, SQLite, MariaDB, and T-SQL.
Base64 / URL
Encode and decode Base64, Base64URL, and URI components, including file data URIs.
Hash Generator
SHA-1, SHA-256, SHA-384, SHA-512, MD5, and HMAC from text or files in-browser.
Unix Timestamp
Convert epoch seconds and milliseconds to ISO time, local time, and time zones.
Pretty SQL
SQL beautifier
cURL → Go
Go from DevTools
Unix timestamp
Epoch ↔ date
UUID v4 vs v7
Primary key guide
Looking for pretty SQL? Open the Pretty SQL alias (same formatter, PostgreSQL-friendly SEO page).
Guides
UUID v4 vs v7: Which Should You Use? (2026 Guide)
UUID v4 vs v7 for primary keys in 2026 — randomness, index locality, timestamp leakage, and when NanoID or auto-increment still wins. With a comparison table and code examples.
9 min read
JWTs in practice: RFC 7519 without the hand-waving
How JSON Web Tokens are structured, which claims matter, why alg none is dangerous, and how to inspect tokens without leaking them to a hosted debugger.
9 min read
Typing JSON in TypeScript: samples, Zod, and trust boundaries
Why inferred interfaces from sample JSON are a starting point, not a contract, and how Zod (or another parser) belongs at every trust boundary.
8 min read
Why developer tools should run in your browser
The privacy, latency, and AdSense-era content problem of hosted utilities — and how a static, client-side suite avoids uploading secrets.
6 min read
Payment test cards documentation
Stripe, Razorpay, and PayPal sandbox PANs — success and decline cards, 3D Secure, UPI test IDs, test mode setup, and troubleshooting.
Documentation
App Icon Studio documentation
Documentation for designing, previewing, and exporting iOS AppIcon.appiconset packs, Android adaptive icons, PWA assets, promo badges, store marketing frames, and batch variants.
Documentation
Third-party APIs
IFSC, PIN codes, geocoding, IP geolocation, dummy JSON REST, weather, FX, and more — with Free / Freemium / Paid labels and official-docs links.
Browse the catalogue