148 tools
Time to stir your life and switch your drink
Pick the higher one · Puzzle of the day — stay and play
No tool matches. Try other words, or browse the full list below.
What I use
Dev tools22
CompareNewLine diff · Structural diff (moves separated) · Merge picked parts
curl converterNewcurl → fetch/axios/python/go/node/httpie · no lost quotes or headers
Mock data makerNewOne field per line · fixed seed · ko/en/ja · JSON, CSV, SQL
Table relationsNewDDL · Prisma · entity relationships · export as mermaid
Diagrams from textNewFlowchart · ER diagram · Download as SVG · Syntax check
Version rangesNewExpand a range into bounds · Does this version match · Do two ranges overlap
Security headersNewSplit the header · Spot the parts that are effectively off · Build one
API tryoutNewOperation list · example request · example response · table for your mock server
protobuf decoderNewReadable without a schema · names from .proto · base64 or hex in
SSH key viewerNewRead authorized_keys lines · SHA256 fingerprint · PEM → OpenSSH
Ranges & portsNewCIDR maths · overlapping ranges · host counts · port lookup
Base64 encode · decodeNon-Latin safe · URL-safe · both directions
Encrypt / decryptAES encrypt·decrypt · Base64 · URL encoding
CSV ↔ JSONBoth directions · pick the delimiter · numbers detected
Table convertSpreadsheet paste detected · aligned Markdown pipes · CSV·JSON · column-mismatch warning
JSON formatterFormat · tree view · copy path · error location · fix common mistakes
Hash generatorMD5 · SHA-1 · SHA-256 · SHA-512 · file checksum match
UUID generatorUUID v4·v7 · ULID · NanoID · random passwords
Regex testerLive matching · capture groups · replace preview · pattern presets
URL encode · breakdownEncode · decode · break out parameters · remove trackers
JWT decoderHeader · payload · expiry · time left
Cron expression readerPlain-language reading · next 5 runs · common examples
Calculators15
Unit converterLength·weight·area·temperature · pyeong↔m² · price per pyeong
Number base converterBinary·octal·decimal·hex at once · any base 2–36 · bit count
Number ↔ Korean wordsRead in Korean · back to digits · formal amount wording
Aspect ratio calculatorRatio-locked sizes · screen ratio list · margin calculation
GPA calculator4.5 and 4.3 scales · weighted average · work back from a target
VAT calculatorAdd · extract · copy the three lines
Byte unit converter1000-based · 1024-based · where they differ
Business number checkCheck-digit validation · business type · catches typos
Loan repayment tableThree methods compared · grace period · what paying extra saves · download the table
CSS unit converterpx · rem · em · pt · % · a table of common sizes
Percentage calculatorDiscount · change rate · ratio · recover the original value
Split the billNewExact to the last won · Fewest transfers · Integer-only math
Take-home payNewTake-home pay · four insurances · tax-free allowance · shows the rate year
Interest calculatorSavings · deposits · loans · after-tax amounts
BMI calculatorTwo standards side by side · normal weight range · standard weight
PDF tools11
PDF to image1×–4× scale · PNG·JPG · pick the pages
Image to PDFA4·Letter·B5·original size · margin control
Printable paperNewGrid · manuscript · staves · calendar · labels · millimetre-accurate · SVG/PDF
PDF watermarkKorean supported · opacity·size·angle · no upload
PDF editorMerge · extract pages · delete · rotate
Sign PDF onlineDraw by hand · place it on the preview · resize · no upload
PDF to textLines and paragraphs restored · page range · copy or save as txt · no upload
Crop PDFCrops with the text intact · every page the same size · scan smudges ignored · no upload
PDF page numbersSkip covers · start at 1 from the body · "1 / 12" or "page 3" styles · no upload
PDF redactionThe text really is gone · hidden notes and annotations too · page count kept · no upload
Compress PDFFirst-page preview · quality·resolution control · resulting size shown · no upload
Everything else8
Image editorCrop · resize·reformat · brightness correction
Image resizerBy long edge, ratio or file size · inside your browser
Remove backgroundNewID photos · product shots · scans · download as transparent PNG
ID photoNewPassport / ID / visa specs · eye-height guides · print layout · stays in your browser
Document scanNewDrag four corners · undo the perspective · scan look · fit to A4
Read text in imagesNewSort the job · flatten and clean · extract text · model only when needed
RedactErased, not covered · blackout or mosaic · location data stripped too · no upload
Image to ASCII artImage → character art · 5 character sets · save as text or PNG
Time8
Timer · stopwatchCountdown · stopwatch · laps · end chime
Birthday factsThree age counts · zodiac·star sign·birthstone · next birthday D-day
Business day calculatorN business days out · business days between · holidays and substitutes · the dropped days listed
Time add · subtractAdd/subtract clock time · total hours worked · decimal hours
Running pacePace ↔ speed · 5K·10K·half·full · work back from a goal
Date calculator · countdownD-Day · between two dates · weekdays only · 100-day and anniversary marks
Unix timestamp converterSeconds/milliseconds detected · ISO · UTC · relative to now
World clock · offsets40+ cities · offsets · daylight saving handled
File tools7
ZIP file maker · extractorBundle · list contents · extract individually · compression level
Bulk image converterBatch convert · size cap · JPG·PNG·WebP · ZIP
File checksum (MD5 · SHA)SHA-256·SHA-1·SHA-512 · automatic comparison
Favicon generator6 sizes · .ico included · true-size preview · markup provided · no upload
Photo stitchVertical or horizontal · width matching · gap between · preview · no upload
Split and join large filesPick the piece size · order sorted automatically · checksum confirms the match · no upload
EXIF removerSee the coordinates · removed without re-encoding · no upload
Video tools7
Video to GIFPreview the range · size·fps·color count · preview after building · size estimate
Video to audioLength·sample rate·channels shown · save as MP3/WAV · no upload
Video trimmerPreview the range · sound kept · check before saving · no upload
Video rotate90·180·270° · dimensions swapped automatically · mirror flip · sound kept · no upload
Compress videoPick size and quality · estimated size · check before saving · no upload
Video → stillsThis frame · every N seconds · PNG/JPG/WebP · ZIP · no upload
Screen recorderPick screen or window · system sound + mic · elapsed time and size · no upload
Reference tables7
HTTP status codes1xx–5xx · names · one line on when to use it
Keyboard event codesPress and see · event.key · event.code · keyCode
Markdown syntaxGFM · paste-ready snippets · search by category
Regex cheatsheetSymbols · quantifiers · anchors · full patterns · common snags
git commandsSearch by situation · dangerous commands flagged · click to copy
File extensionsWhat is this file · what opens it · by category
Keyboard shortcutsWindows · macOS · browser · VS Code · Korean input
Audio tools6
Audio speedPitch preserved · 0.5×–3× · 0.75× for transcription · no upload
Audio fadeClick diagnosed automatically · only as much as needed · ear-matched curve · no upload
Audio joinSample rate matched · silence between · fades at the seams
Audio trimmerWaveform view · preview the range · fades · save as MP3/WAV
Normalize audio volumeBefore/after waveforms · even out then raise · listen before saving · no upload
Voice recorderLive input level · silence and clipping warnings · save as MP3/WAV
Color tools6
CSS gradient generatorLive preview · linear·radial · angle control · muddiness compared · copy CSS
Color contrast checkerContrast ratio · accessibility verdict · a passing color suggested
Color vision simulatorProtan · deutan · tritan · achromatopsia · distinguishability verdict
Color converter (HEX · RGB · HSL)HEX·RGB·HSL·CMYK · pick a color off the screen · contrast and palettes
Extract image colors4–64 colors · HEX · RGB · copy as CSS variables
CSS color names148 colors · name ↔ HEX · grouped by family
Character map4
Special charactersArrows · stars · shapes · math · units · brackets — click to copy
ASCII table0–127 · decimal · hex · binary · what the control codes mean
HTML entities · < · © — copies the code you put in markup
Emoji finderKorean search · by category · click to copy
Random draw3
Lottery number generatorLotto 6/45 · Pension Lottery 720+ · auto-check against the latest draw · winning odds
Ghost legUp to 10 players · watch the path · copy the result
Draw · team splitDraw · split into teams · set an order
QR tools2
QR code generatorURL·WiFi·contact · logo overlay · reads its own QR back to verify
QR code readerImage·paste·camera · tells you the content type · no upload
Everything else30
Morse codeBoth directions · Korean Morse · sound and light playback
Text toolsCount · tidy · compare · case · Korean-English key
Moon PhaseTonight's moon · phase name
NotepadMultiple notes · autosave · this browser only
Password generator · strength checkRandom · pronounceable chunks you can remember · strength check
Subtitle timingTime shift · frame-rate drift correction · SRT↔VTT · first and last line checked · no upload
Calendar file makerTime zones handled · all-day·recurring·reminders · spec violations prevented · no upload
Barcode generatorCode128·EAN-13 · check digit automatic · quiet zone guaranteed · no upload
PDF revision compareText and image compared · only the changes highlighted · finished inside the browser
Ghost typing duelYour typing run becomes a link · duel over any text · never expires
Lightning duelFew-second mini-games, one on one · one link and you are in · match with anyone · no room on a server
Time capsule letterNobody opens it before the day · no server holding it · changing the clock does not help
Chain toolsEach result feeds the next · every step visible · up to 8 steps
Today’s Hangul typingThree sentences a day · the same for everyone · keystrokes and accuracy
Today’s consonant quizFive puzzles a day · the same for everyone · the answers are tool names
Character conversionFull/half-width · Roman letters · jamo · a warning for mixed characters
Comparison sliderSlide between before and after · different sizes are fine · save as PNG
Elapsed time counterClimbs by the second · by the calendar · rough conversion
3D viewerOpen without installing · turn it around · triangle count and size
Developer study mapNew41 tracks · 311 cards · a lesson on each · check questions · progress saved
ArcadeNewNine mini games · solo or together · bots fill empty seats · rooms never stored on a server
Bundle mapNewwebpack · esbuild · heaviest paths · duplicate packages
Log viewerNewISO · syslog · nginx · JSON lines · spike timeline · level filter
Find similar photosNewBurst shots · survives resize and recompression · 64-bit dHash · stays in your browser
Photo locationsNewEXIF place and time · grouped by date · dots only · nothing leaves the browser
Read aloudNewSentence splitting · time estimate · browser voices · nothing to install
Call graphNewimport/require graph · cycles · entry points and dead files · no heavy parser
TerritoryNewEach pixel is painted the color of its nearest store · area share · top brand per province and district
My AINewLeft per subscription · time until reset · last observed value when blocked
My Writing AtlasNewNotes → terrain · peaks and valleys · buried notes · pairs to link · a control beside every number
Every tool computes inside your browser; what you type is never stored or sent. See all of KarmoLab · Who made this