277 Free Online Tools
QR codes, image conversion, video processing, text utilities — no signup, no watermarks.
Kits — curated tool bundles
View all →QR Code (6 tools)
QR Code Generator
Convert URLs, Wi-Fi credentials, vCards, and text to QR codes. Download as watermark-free PNG/SVG, free forever, no signup required.
Wi-Fi QR
Turn Wi-Fi name and password into a QR code so guests can connect with a single scan. Perfect for cafes, restaurants, and Airbnb hosts.
vCard QR
Encode name, company, phone, and email into a QR code. Scan to save the contact instantly — print on paper business cards for one-second exchanges.
QR Code Reader
Upload an image containing a QR code and it's decoded automatically. Works with Wi-Fi, URL, and vCard QRs. Use it on a PC without a camera.
QR with Logo
Insert a logo or icon into the center of a QR code — great for branded QRs. Error correction level auto-adjusts. Useful for café/shop logo QRs, business cards, event posters, brochures, and wedding invitations.
QR with Text
Insert text (shop name, person's name, event title, brand) in the center of a QR code, with free color and background shape options. Use it instead of a logo image for store signage, business cards, event posters, or labeling a Wi-Fi QR with the network name.
Image (38 tools)
Background Remover
Automatically remove the background from photos of people or objects and save as a transparent PNG. The AI model runs entirely in your browser — your photos are never uploaded. Great for profile photo cutouts, product photos, ID photos, sticker making, and compositing.
Aspect Ratio Calculator
Keep an aspect ratio (e.g. 16:9) and enter just the width or height — the other is calculated automatically. Useful for matching video resolutions, thumbnail/banner sizes, image resizing, and monitor/design work. Also reverse-calculates the ratio from two dimensions.
Color Blindness Simulator
Simulate how an image or color appears to people with color vision deficiencies — protanopia (red-blind), deuteranopia (green-blind), tritanopia (blue-blind), and achromatopsia. Useful for web/app accessibility checks, contrast verification, and infographic/chart color choices. Processed in your browser.
PNG → JPG
Instantly convert PNG images to JPG. Processing happens entirely in your browser — files are never uploaded. Adjustable quality, free, no signup.
JPG → PNG
Convert JPG images to PNG. PNG is lossless, ideal for print and editing. Processing happens safely in your browser.
WebP → JPG
Convert WebP images to JPG. Solves compatibility issues when attaching to messengers or documents that don't support WebP.
Barcode (9 tools)
Barcode Generator
Generate all major 1D barcodes — Code 128, EAN-13, EAN-8, UPC-A, Code 39, ITF-14, Codabar — in one place. Download as PNG/SVG, customize colors, toggle text. Useful for retail price tags, library labels, asset tracking, shipping invoices, pharmacy management, and student IDs.
Barcode Reader
Automatically decode almost any barcode from images — EAN-13, Code 128, Code 39, UPC, ITF, QR, DataMatrix, PDF417, and more. Decode without a camera right in your PC; photos are processed in the browser and never uploaded. Useful for checking product photos, verifying printed labels, extracting ISBNs from book photos, and analyzing receipts.
EAN-13 Barcode
Generate EAN-13 barcodes — the global retail product barcode standard (Korea uses prefix 880). For store price tags, self-made product labels, small-business POS systems, and warehouse labels. The check digit is auto-calculated: enter 12 digits and the 13th is added.
EAN-8 Barcode
Compact EAN-8 barcodes for small items where a full EAN-13 label won't fit — lip balms, candy, small parts. Enter 7 digits and the check digit is auto-added.
UPC-A Barcode
US/Canada retail product barcode standard. 12 digits (manufacturer + product + check). Required for US retail, Amazon FBA, and US-bound exports. Korean products sold in the US often need UPC-A instead of EAN-13.
ISBN Barcode
Enter ISBN-10 or ISBN-13 to generate the EAN-13 barcode. ISBN-10 is automatically converted to ISBN-13 with the 978 prefix. Use it for book covers, library cataloging, publication registration, and independent author cover design.
Video (18 tools)
Video → GIF
Convert MP4, MOV, WebM videos to animated GIFs. Adjustable FPS, size, and length. Files are processed in your browser and never uploaded.
Video → MP3
Extract audio from videos like MP4 and save as MP3. Useful for lectures, interviews, and music videos. Processing happens in your browser.
Video Compress
Reduce video file size by 50–80% with minimal quality loss. Solves upload size limits on messengers, email, and forums.
Video Trim
Cut out the section of a video you want. Set start and end points with sliders. Lossless fast cutting (stream copy method).
Subtitle SRT/VTT Editor
Convert between SRT and VTT subtitle files and shift timing by an offset to fix sync. Extract plain text too.
Video Editor (All-in-One)
Trim, rotate, flip, change speed, mute, resize, and compress in a single tool. Combine multiple edits in one ffmpeg.wasm pass to minimize quality loss.
Documents & Office (21 tools)
HWP Viewer
Open .hwp and .hwpx files directly in your browser — no Hancom Office required. Page navigation and zoom supported. Files never leave your device.
HWP → Text
Extract body text from Korean HWP documents as .txt. Useful for pasting into messengers, email, or translators. Safe browser-based processing.
HWP → PDF
Convert Korean HWP documents to PDF instantly — no Hancom Office needed. Perfect for sharing or printing.
HWP → HWPX
Convert legacy .hwp files to the Korean government standard .hwpx format (KS X 6101). Useful for public-sector submissions and modern tool compatibility.
HWPX Editor
Write text and pick a font and size, then save as a Korean-standard HWPX file (KS X 6101) — no Hancom Office required. Useful on machines without a Hancom license.
PPTX Viewer
Open PowerPoint (.pptx) files right in your browser and preview the slides — no PowerPoint install needed. Files are processed on your device and never uploaded. Great for quickly checking decks you received, viewing on a PC/tablet without PowerPoint, and previewing attachments.
Calculator · Life (56 tools)
Korean Car Tax
Compute annual Korean car tax and local education tax from engine displacement and vehicle age. Supports sedans, business vehicles, hybrids, and EVs.
Severance Pay Calculator
Estimate Korean statutory severance pay from tenure, average wage, bonus, and unused leave. Useful before resignation, retirement, or comparing DB vs DC pension schemes.
Korean Income Tax
Estimate Korean comprehensive income tax from gross income, expenses, and deductions. For May tax-filing season self-checks, freelance/rental income estimates.
Real Estate Tax (KR)
Compute Korean acquisition, transfer, and property taxes — single vs multi-home, holding period, capital gain progressive rates, and standard-value property tax.
Pomodoro Timer
25-min focus + 5-min break cycles for productivity. Long break every 4 cycles, sound + browser notifications, cycle statistics.
Trip Cost Split
Split travel or dining expenses among members with minimum-transfer settlement. Per-expense partial sharing, greedy optimization.
Text (36 tools)
Speech to Text (STT)
Convert speech to text via your microphone. Korean / English / Japanese / Chinese supported. Great for meetings, interviews, lecture notes, and pronunciation practice.
Hanja Dictionary
Look up ~170 common hanja with Korean reading, meaning, stroke count, and Korean Hanja Proficiency Test grade.
Markdown TOC
Automatically analyze H1–H6 headings in your markdown to build a Table of Contents. Indentation and anchor links handled automatically. Great for GitHub READMEs, tech blog posts, Notion pages, study notes, and meeting minutes.
Markdown Table
Set row/column counts, fill in cells, and the markdown table syntax is generated automatically. Add/remove cells, choose alignment, live preview. Great for GitHub README comparison tables, tech blog spec tables, Notion and Obsidian notes, and meeting decisions.
Hangul → Roman
Convert Korean Hangul to romanization using the National Institute of Korean Language's Revised Romanization standard. Useful for English business cards, passport name spellings, overseas hotel reservations, and SNS English nicknames.
Morse Code
Convert text to Morse code and back. Supports English, numbers, and Korean jamo, with audio playback. Useful for Morse learning, amateur radio (ham) exam prep, military comms study, coding study aids, and fun message encoding.
Developer (65 tools)
Mermaid Diagram
Draw flowcharts, sequence diagrams, Gantt charts, class diagrams, and pie charts from text code. Embed-ready for GitHub README, Notion, Obsidian. Download SVG/PNG.
Age Calculator (Western/Korean)
Enter your birth date and see Western (international) age, Korean counting age, and yeonnai (year age) at once. Reflects Korea's June 2023 standardization to international age. Useful for paperwork, medical prescriptions, insurance, job applications, and confirming legal age for alcohol or tobacco.
Lunar ↔ Solar
Convert Korean lunar and solar dates in both directions. Range 1391–2050, leap month support, and ganji display. Useful for converting your parents' or grandparents' lunar birthdays to solar, ancestral rites date conversion, checking Lunar New Year and Chuseok dates, and entering data for fortune telling.
Caesar Cipher / ROT
Encrypt and decrypt text with Caesar cipher. ROT13/ROT47 presets and custom 1–25 rotation. Useful for CTF challenges, hiding spoilers on forums, introductory cryptography study, and fun message encoding.
HTTP Status Codes
Search the meaning of HTTP response codes 100–599. RFC standard codes plus common non-standard ones (418, 429, etc.). Useful for API debugging, error screen analysis, backend response design, interview prep, and web dev study.
CSS Gradient
Build linear/radial gradients visually by adding and adjusting color stops, then copy the CSS code. Live preview. Useful for website backgrounds, button designs, card UI headers, mobile app gradients, and marketing page backgrounds.
PDF (20 tools)
PDF Unlock
Check whether a PDF is password-protected, right in your browser. Browser PDF libraries cannot decrypt files, so removing a password is not possible here — encrypted files are reported as such. PDFs without a password can be re-saved in a standard form to clean up viewer errors.
PDF Merge
Combine multiple PDFs into one. Drag to reorder, and files are processed in your browser and never uploaded.
PDF Split
Split a PDF by page or extract specific page ranges. Receive everything as a single ZIP.
PDF Rotate
Straighten sideways or upside-down PDF pages. Rotate all pages or specific pages by 90/180/270 degrees.
PDF Delete Pages
Remove blank or unnecessary pages from a PDF. Just select page numbers and hit delete.
Images → PDF
Combine photos and scans into a single PDF. Supports JPG/PNG/WebP, choose page size, free reordering.
Citation · Essay (8 tools)
Citation Formatter
Enter author, year, title, and journal to generate all five major citation formats at once: APA 7, MLA 9, Chicago, Harvard, and IEEE. Supports journals, books, and websites. Useful for paper writing, thesis references, and conference-format conversions.
DOI · ISBN Lookup
Paste a DOI or ISBN, and CrossRef / Open Library APIs fetch metadata to generate APA, MLA, and Chicago citations. Great for accurate one-click references during paper writing — no more citation typos.
BibTeX Converter
Convert LaTeX BibTeX entries into plain-text APA, MLA, or Chicago references. Helpful when moving a paper into Word or Hancom Office, cleaning up exports from Zotero/Mendeley, or meeting different conference style requirements.
Bibliography Sorter
Sort a reference list alphabetically or by Korean Gananada order, remove duplicates, and preview hanging-indent formatting. Useful for last-minute paper polish, merging references from multiple authors, and citation cleanup.
Title Case Converter
Auto-capitalize English paper or essay titles per APA, Chicago, and MLA rules. Short prepositions and conjunctions stay lowercase. Useful for paper titles, English presentation decks, book covers, and English resumes.
Academic Citation
Auto-generate academic citation entries in APA 7th, MLA 9th, Chicago Author-Date, and Harvard styles — both the reference list entry and the in-text citation. Useful for theses, journal submissions, and student papers.