KarmoLab

Base64 를 텍스트로 되돌린다. URL-safe 표기와 빠진 = 채움도 함께 처리한다.

Encode text to Base64. Handles non-ASCII via UTF-8, so Korean does not break (plain btoa does). / 텍스트를 Base64 로. 한글 안 깨짐.

From a birth date: the three Korean ages (international / year-age / traditional), zodiac, star sign, weekday born, days lived, next birthday. Korea still uses all three ages in different laws, so all three are returned. / 한국식 나이 3종·띠·별자리·태어난 요일·산 날수·다음 생일.

Validate a Korean business registration number (10 digits) or corporate registration number (13 digits) against its check-digit rule. Format only — it cannot tell you whether the number is actually registered (that needs the NTS lookup). / 한국 사업자등록번호·법인등록번호가 검증 숫자 규칙에 맞는지 계산한다. 형식만 본다.

Count text every way at once — with/without spaces, words, sentences, lines, paragraphs, UTF-8 and EUC-KR bytes, Korean manuscript pages, and a breakdown by script. Emoji count as one character as a person sees them (naive .length says 2–7 for one emoji). / 글자수를 여러 기준으로 한 번에. 이모지는 보이는 대로 한 글자.

Check whether text fits a limit, choosing the basis (with/without spaces, or bytes) — forms disagree on which one they mean. / 한도에 들어가는지. 기준을 골라서.

JSON 배열을 CSV 로 바꾼다. 값에 쉼표·따옴표·줄바꿈이 있으면 규칙대로 감싼다.

CSV 를 JSON 배열로 바꾼다. 따옴표 안의 쉼표·줄바꿈을 규칙대로(RFC 4180) 처리한다. delimiter 기본은 쉼표, coerce 를 켜면 숫자/true/false/null 을 그 타입으로 바꾼다.

Days, weeks and weekdays between two dates — reported both inclusive and exclusive of the end date, because that off-by-one is the whole argument. / 두 날짜 사이 일수·주수·평일수. 끝날 포함/제외 둘 다.

Days until (or since) a target date. Reports both the D-Day convention (start day counts as day 1) and the plain difference — they differ by one and that is where the confusion lives. / D-Day. 관례 계산과 단순 차이를 함께.

Add or subtract days/weeks/months/years. Jan 31 + 1 month clamps to the last day of February instead of rolling over into March, which is what naive date math does. / 날짜 더하기·빼기. 없는 날은 그 달 마지막 날로.

Turn a Unix timestamp into a readable time, detecting seconds / milliseconds / microseconds / nanoseconds from the digit count — guessing wrong lands you in 1970 or the year 55000. / 유닉스 타임스탬프 → 사람이 읽는 시각. 단위 자동 판별.

ISO 8601 시각을 유닉스 타임스탬프(초)로 바꾼다.

Compare two checksum strings. Publishers hand out values in mixed case, with a `sha256:` prefix, or wrapped across lines — comparing those literally reports "different" for identical files. / 체크섬 두 개를 맞춰 본다. 대문자·머리말·줄바꿈을 정리해서.

Korean university GPA from "credits grade" lines, e.g. "3 A+\n3 B0\n2 A-" — credit-weighted, not a plain average. scale = 4.5 (default, the Korean norm) or 4.3. / 학점 가중 평점. scale 45(기본)·43.

What average the remaining credits must earn to reach a target GPA — and it says so plainly when even straight A+ cannot get there. / 목표 평점에 필요한 남은 평균. 불가능하면 불가능하다고.

Detect the direction and convert. Any Hangul present means Hangul → keys. / 어느 쪽인지 알아서 판단해 반대로 바꾼다.

Turn Hangul into the 2-beolsik key sequence. 안녕하세요 → dkssudgktpdy. / 한글을 두벌식 자판의 영문 키 나열로.

Recover Hangul typed without switching the IME (2-beolsik layout). dkssudgktpdy → 안녕하세요. Not a substitution table — it replays the composition automata (final consonants move to the next syllable when a vowel follows). / 한영키를 안 누르고 친 영문을 한글로 되돌린다.

Hash a string to hex — the value an LLM will otherwise invent. Give algo for one, omit for all 7 (MD5, SHA-1, SHA-256, SHA-512, SHA3-512 (FIPS-202), Keccak-512 (pre-standard), RIPEMD-160). SHA3-512 and Keccak-512 are listed separately on purpose: most libraries call Keccak "SHA-3" and the values differ. / 문자열 해시를 16진수로. algo 를 주면 그것만, 안 주면 7종 전부.

Korean time deposit (simple interest) — maturity interest and the amount actually received, after the 15.4% interest income tax that quoted rates never include. / 정기예금 단리. 이자소득세 15.4% 반영.

Equal-payment loan — monthly payment, total repaid, total interest. / 원리금균등 대출. 월 상환액·총 상환액·총 이자.

Korean installment savings (simple interest). Only the early deposits earn a full year, so the real interest is roughly half of total × rate — the single most common money miscalculation here. The gap is shown explicitly. / 정기적금 단리. 「총액 × 연이율」과의 차이를 함께.

Extract only the initial consonants (ㅎㄱ ← 한글) — for building a Korean initial-search index. / 초성만 뽑는다. 초성 검색 색인용.

Recompose a jamo sequence (ㄱㅏㅇ) back into syllables (강) — e.g. filenames that came out of macOS decomposed (NFD). / 자모 나열을 다시 글자로. NFD 로 풀린 파일 이름 되돌리기.

Split Hangul syllables into initial / medial / final jamo, and extract initials (used for Korean initial-consonant search). Compound finals (ㄳ ㄺ ㅄ) stay whole. / 한글을 초성·중성·종성으로 쪼갠다. 초성 뽑기 포함.

Compare all three repayment methods side by side — total interest and first-month payment, the two numbers that actually decide the choice. / 세 상환 방식 비교. 총이자·첫 달 상환액.

Full amortization schedule. method = equal (equal payment, default) | principal (equal principal) | bullet (interest-only then lump sum). grace = interest-only months, extra = extra paid monthly. / 대출 상환표. 원리금균등·원금균등·만기일시, 거치·추가상환 포함.

Rate a password by guessing cost, not by character classes. The usual "has upper, lower, digit, symbol" rule passes Password1! and fails correcthorsebatterystaple — exactly backwards. This scores common words, leet substitutions, sequences, repeats, years and keyboard runs as single cheap chunks, and reports the LOWER of that and the naive pool entropy, plus crack time at offline (1e10/s) and online (100/s) rates. / 비밀번호 세기를 「뚫는 비용」으로 잰다. 글자 종류 규칙 X.

Make a contact (vCard) QR — scanning it adds the contact directly. / 연락처(vCard) QR.

Make a QR code as SVG — no external API, so the contents never leave the machine. level = L/M/Q/H error correction (default M), size in pixels. / 내용을 QR SVG 로. 외부 API 없음.

WiFi 접속 QR 을 만든다. 스캔하면 그 네트워크에 바로 붙는다. encryption = WPA(기본) · WEP · nopass. 비밀번호에 ; : , \ 가 있어도 규칙대로 처리한다.

Convert a table between formats, detecting the input (Excel paste / CSV / Markdown) on its own. Column widths count CJK characters as two cells, so aligned Markdown actually lines up. to = markdown (default), csv, tsv, json. / 표 꼴 변환. 들어온 꼴은 스스로 알아본다.

Add or subtract a duration from a time, rolling into the next day past 24:00. duration accepts "1:25", "85m" or "1.5h". / 시각에 시간 더하기·빼기. 자정 넘김 처리.

Sum durations (timesheets). One per line; "7:45", "8h" and "90m" can be mixed — base-60 addition is where hand-tallied hours go wrong. / 시간 합계. 한 줄에 하나, 표기 섞여도 됨.

Convert units, including Korean/Japanese traditional ones — pyeong(평), geun(근), don(돈), nyang(냥), doe(되), mal(말), ja(자), ri(리). Models answer these with rounded folklore (1 pyeong is 3.3057851 m², not 3.3 — on an apartment that gap is visible money). No currency here: that would need live rates. / 단위 변환. 한국·일본 전통 단위 포함. 환율은 없다.

List available units by category. / 쓸 수 있는 단위 목록.

Generate IDs from a cryptographic RNG. An LLM asked for a "random" value returns something from its training data — using that as a token or password is a hole. kind = uuid4 (default), uuid7 (sortable by time), ulid, nanoid, password. count, length (nanoid/password), symbols (password). / 암호학적으로 안전한 난수로 ID 생성.

Add Korean VAT to a net amount (net × 1.1). Rounds so that net + VAT equals the total exactly — rounding the three lines separately makes them disagree by a won. / 공급가에 부가세를 더한다. 세 줄이 서로 맞게 반올림.

Extract the net amount and VAT from a VAT-inclusive total (total ÷ 1.1), which is NOT the same as subtracting 10% — that common shortcut gives 99,000 instead of 100,000 for a 110,000 total. / 총액에서 공급가·세액을 빼낸다. 10% 를 빼는 것과 다르다.

Word frequency, with Korean particles (을/를/에서는…) stripped so inflected forms collapse. Without that, 도구를 / 도구가 / 도구는 count as three different words and the top list is useless. Also returns repeated two-word phrases. / 낱말 빈도. 한국어 조사를 떼어 같은 말로 묶는다.

N business days after a start date — excluding weekends, public holidays AND substitute holidays. Substitute holidays are a table, not a rule (2025-01-27 was a one-off). Years not in the table are reported as unknown instead of guessed. region defaults to KR (JP/US also available). / 영업일 N일 뒤. 주말 + 공휴일 + 대체공휴일 제외.

Count business days between two dates, and list which days were skipped and why (a bare number cannot be checked). / 두 날짜 사이 영업일 수. 어떤 날을 뺐는지도 함께.

Convert a time from one zone to another, applying DST as it stood on that date (not as it stands today). Zones are IANA names: Asia/Seoul, America/New_York. / 도시 간 시각 변환. 그 날짜의 서머타임 반영.

Offset between two zones for a given date. It will disagree with the number you memorised: DST moves it twice a year, and the two hemispheres do not move together. / 두 시간대 시차. 그 날짜 기준 — 외운 숫자와 다를 수 있다.