Free online tools

Everyday tools, all in one place.

No install, no signup — all free, ready to use.

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Character & Word Counter

Count characters, words, sentences in real-time.

Text Replacer

Replace multiple words at once across your text. Stack any number of rules and optionally use regex with capture groups.

QR Code Generator

Convert text, URLs, Wi-Fi info, and contact details into QR codes. Customize colors and download as PNG or SVG.

Age Calculator

Calculate your exact age in multiple ways: legal age (Korean), calendar-year age, and traditional Korean counting age. See your zodiac sign, birth day of week, and more.

How-To Guides

Step-by-step guides — installing Claude Code, issuing API tokens — with images, diagrams, and code.

Unit Converter

Convert everyday measurements instantly

Lunar-Solar Calendar Converter

Convert dates between lunar and solar calendars, and discover the sexagenary cycle and zodiac animal for any year.

New

Birthday Secrets

Enter your birthday to reveal your birth flower, birthstone, and birth color — with the meaning of each. A playful birthday almanac.

My IP Address

Find your public IP address (IPv4 and IPv6) instantly.

Decision Roulette

Spin to decide fairly from your options.

Lotto Number Generator

Generate fair lottery numbers with cryptographic randomness. No odds guarantee — for entertainment only.

Ladder Game

Climb down the ladder and get your prize. A fair lottery game.

Speed Quiz Prompt Words

A party & classroom speed-quiz game: reveal category prompt words (animals, food, Olympics & more) one at a time on a big screen and race the timer to guess.

JSON Formatter & Validator

Format, validate, and analyze JSON with ease

JWT Decoder

Decode JWT tokens, extract claims, verify signatures

Base64 Encoder/Decoder

Convert text and files to/from Base64 with UTF-8 integrity. Supports both standard and URL-safe variants.

URL Encoder

Encode and decode URLs and edit query strings. Supports UTF-8 and EUC-KR (legacy Korean URLs).

Cron Expression Parser

Convert Unix cron expressions to human-readable descriptions and compute upcoming run times.

Transparent Background Maker

Remove solid-color backgrounds locally. No upload.

New Word Glossary

A bilingual dictionary of trendy MZ slang and modern tech terms, with meanings and examples in Korean and English.

Various Rankings

Curated rankings across movies, music, games, and more.

Restaurant List

Explore curator-picked restaurants by region, cuisine, and category on the map.

Q&A a Day

Answer one daily question and keep a year-long personal reflection journal.

Curated Bookmarks

Find trusted curated links across architecture, frontend, design, development, and more.

Everyone's Cheer

Show your cheer message big — wave it like an LED banner at concerts and games.

Developer People Dictionary

Explore stories of influential software engineers and computer scientists who shaped technology history. From programming language designers to open-source pioneers and architecture visionaries.

Knitting Gauge Calculator

Calculate cast-on stitches/rows from your gauge and rescale patterns

Charades

A silent-acting party game — reveal prompt words one at a time on a big screen by category (actions, animals, jobs, and more), then act them out using body language only, no talking.

Barcode Generator

Generate EAN-13, UPC-A, Code 39, and Code 128 barcodes for free. Download as PNG or SVG.

Why Jurepi?

Jurepi is a free collection of the small tools you reach for every day — calculators and converters, text and developer utilities, random pickers and games — all in one place. There's nothing to install and no account to create; each tool runs right in your browser. Open it when you need it, close it when you're done.

Instant, no sign-up

No login, no install, no payment. Open the link and the tool runs immediately, with every feature free to use.

Safe in your browser

Whatever you type is processed inside your own browser. Nothing is sent to a server or stored remotely, so your data never leaves your device.

Grows by request

Ask for a tool or feature and it gets built and added, one at a time. Only tools born from real use make it in.

What's inside?

You'll find calculators (age, unit, and lunar-calendar conversion), text tools (character counting, find & replace), converter and developer tools (URL, Base64, JSON, QR, JWT), random pickers (ladder game, roulette), journaling and bookmarks, plus fun and news/ranking tools. Search the list below or browse by category to get started.