Free Online Tools for Developers & Designers
Formatters, generators, and converters for daily work - all running in your browser. Nothing uploaded, no sign-up, no install.
Developer Tools
Formatters, encoders, and references for daily engineering - JSON / YAML / CSV / XML conversion, SQL formatter, Base64, UUID v1/v4/v7, HTTP status codes, and a Git commands cheat sheet.
🌿 Git Commands Cheat Sheet
The most used Git commands organized by category. Copy any command with one click.
Open →🧰 JSON Formatter & Converter
Format or minify JSON and convert between YAML, CSV, and XML. Auto-detects the input format.
Open →🔐 Base64 Encoder & Decoder
Encode or decode text and files with Base64. Auto-detects whether input is already encoded.
Open →🗃️ SQL Formatter
Pretty-print SQL queries. Supports MySQL, PostgreSQL, and other dialects.
Open →✨ HTML · CSS · JS Formatter
Beautify or minify HTML, CSS, and JavaScript code in your browser.
Open →🆔 UUID Generator
Generate UUID v4 / v7 / NIL up to 10,000 at once. Multiple formats, copy and download.
Open →📡 HTTP Status Codes Reference
Complete reference of HTTP 1xx to 5xx codes with clear explanations.
Open →🏷️ Schema.org Types Guide
Application contexts and rich snippet examples for 11 key JSON-LD structured data types.
Open →Design Tools
Assets for SEO and visual setup - a favicon generator with SVG + PNG + manifest output, image format converter, JSON-LD structured data generator, and an AI-crawler-aware robots.txt generator.
🌐 Favicon Generator
Create favicons from an image, text, or emoji. Download PNG / SVG and copy the HTML embed snippet.
Open → Popular🖼️ Image Compressor & Converter
Convert images to JPG, PNG, or WebP and reduce file size. All processing in your browser.
Open →🏷️ JSON-LD Generator
Generate Schema.org structured data (6 types) from simple form inputs.
Open →🤖 Robots.txt Generator
Generate a robots.txt file to control search engine and AI crawler access.
Open →Productivity
File utilities that stay in your browser - merge images and PDFs into one document and generate placeholder text with Lorem Ipsum. Nothing is uploaded to a server.
Frequently Asked Questions
What is UtilLab?
UtilLab is a free collection of browser-based tools for developers and designers - formatters, encoders, generators, and converters. No sign-up, no installs, and nothing is uploaded to a server.
Is everything really free?
Yes. All tools are free with no paid tier or account required. The site is supported by display ads, and tools work identically whether or not you use an ad blocker.
Where are my inputs processed?
Every tool runs in your browser. Files, text, and tokens you paste never leave your device - safe to use with confidential data, private API keys, or JWT tokens. You can verify this yourself by opening DevTools → Network while you use a tool; no outbound requests are made.
Do you support non-Latin text?
Yes. All tools are Unicode-aware. Text-based tools use TextEncoder/TextDecoder so emoji, CJK characters, and multi-byte UTF-8 round-trip correctly without corruption.
Is there a Korean version?
Yes. The Korean site at utils.spemer.com includes additional tools focused on Korean finance and policy (salary after deductions, housing subscription points, minimum wage, etc.) in addition to the developer tools shared with this site.