Word cards (spaced repetition)
Paste a front/back word list and the Leitner box method adjusts when each card returns based on whether you knew it. Guests save only in this browser; logged-in members save to their account to continue on other devices and share.
Decks and progress are never sent to a server; they are saved only in this browser (localStorage). To use another device, make a backup file and load it there.
Log in to save your decks to your account, continue on other devices, and share a deck by link. Log in
Browser storage is unavailable here, so progress is not saved. It only works for this visit.
Keyboard: Space flips · → got it · ← missed it. Missed cards come back at the end of this session.
How review works & clearing progress
Cards live in boxes 1–5. Got it → up one box (revisit after: box 2 one day · 3 three days · 4 one week · 5 three weeks); missed → back to box 1 and asked again right away. Days follow this device’s today.
- One card per line. On each line, separate the front (word) from the back (meaning) with one of the separators below. The symbols have no special meaning — they just mark where the front ends (e.g. run = to move fast → front: run, back: to move fast).
- Tab: copy two columns from Excel or Google Sheets and paste — they become tabs automatically (the easiest way).
- | and tab work with or without spaces around them: apple|사과
- =, :: and → (or ->) need one space on each side: run = to move fast (without the spaces they are not treated as separators).
- If a line has several separators, only the first one splits it, so the back may contain symbols: a = b = c → front a, back b = c.
- Cards with the same front are merged (case ignored). Up to 500 cards, 200 characters per side.
For CSV the first two columns become front and back. Imported cards are appended to this deck.
FAQ
Can I continue on another device?
If you log in, decks and progress are saved to your account and follow you to any device. Without logging in they stay in this browser only, so use "Download backup" and "Upload backup" on the other device. The first time you log in, the decks already in this browser are uploaded to your account.
How do I send a deck to a friend?
Log in and press "Create share link". Anyone with the link can view it without logging in and take it with "Add to my decks". Only the name and cards are shared, never your progress. Press "Stop sharing" and the link closes immediately.
What if I clear my browser data?
Your decks and progress disappear with it. Download a backup of important decks now and then.
I want two cards with the same front.
Cards are identified by their front, so the same front merges into one. Add a hint after the front, like (noun) or (verb).
How to use this tool
Use it to memorize vocabulary or facts by repetition. Paste front/back pairs and the Leitner box method adjusts how soon each card returns depending on whether you knew it. Your deck and progress are stored only in this browser.
Frequently asked questions
What is the Leitner box method?
A spaced-repetition method: cards you knew come back later and cards you missed come back more often, so you spend time on what you do not know yet.
How do I create a deck?
Paste the front and back of each card and the cards are created.
Where is my progress stored?
Only in this browser. It is not visible on other devices or browsers and disappears if you clear browser data.
Related tools
See all toolsHangul Fixer
Fix Korean text and file names made on a Mac that appear as separated jamo or garbled on Windows. Supports NFD↔NFC conversion, jamo joining/splitting, batch file-name conversion and encoding-mismatch recovery.
Character Counter
Counts characters and UTF-8 / EUC-KR bytes as you type. Handy for cover letters and text-message limits.
Text Cleaner
Remove line breaks, tidy spaces, drop duplicate lines, sort lines, convert full/half-width and straighten quotes in one click. Made for cleaning up copied text.
Markdown Preview
Write Markdown and see the result right next to it. Headings, lists, tables, code, quotes and checkboxes are supported, and you can copy the finished HTML. Optionally preview it with the same renderer the boards use (converted on the server).
Subtitle Editor (SRT · VTT)
Shift a subtitle file’s timing, stretch it to match a video’s frame rate, or fix everything by matching just two scenes. Also converts SRT ↔ VTT, wraps lines, strips tags and flags overlaps and subtitles that flash by too fast. Files are never uploaded.
Typing Practice
Measure your typing speed with proverbs, short sentences and longer passages — keystrokes per minute for Korean, WPM for English — plus accuracy and the characters you got wrong. You can also practise on your own text, and nothing you type is sent to a server.