146 tools

Mock data makerOne field per line, fixed seed, ko/en/ja, JSON, CSV, SQL Diagrams from textFlowchart, ER diagram, Download as SVG, Syntax check Version rangesExpand a range into bounds, Does this version match, Do two ranges overlap API tryoutOperation list, example request, example response, table for your mock server protobuf decoderReadable without a schema, names from .proto, base64 or hex in Ranges & portsCIDR 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 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 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 billExact to the last won, Fewest transfers, Integer-only math Interest calculatorSavings, deposits, loans, after-tax amounts PDF to image1×-4× scale, PNG, JPG, pick the pages Image to PDFA4, Letter, B5, original size, margin control Printable paperGrid, manuscript, staves, calendar, labels, millimetre-accurate, SVG/PDF 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 Image editorCrop, resize, reformat, brightness correction Image resizerBy long edge, ratio or file size, inside your browser Remove backgroundID photos, product shots, scans, download as transparent PNG ID photoPassport / ID / visa specs, eye-height guides, print layout, stays in your browser Document scanDrag four corners, undo the perspective, scan look, fit to A4 Read text in imagesSort the job, flatten and clean, extract text, model only when needed RedactErased, not covered, blackout or mosaic, location data stripped too, no upload 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 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 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 HTTP status codes1xx-5xx, names, one line on when to use it Markdown syntaxGFM, paste-ready snippets, search by category Regex cheatsheetSymbols, quantifiers, anchors, full patterns, common snags Keyboard shortcutsWindows, macOS, browser, VS Code, Korean input 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 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 Emoji finderKorean search, by category, click to copy Lottery number generatorLotto 6/45, Pension Lottery 720+, auto-check against the latest draw, winning odds Draw, team splitDraw, split into teams, set an order QR code readerImage, paste, camera, tells you the content type, no upload Moon PhaseTonight's moon, phase name 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 PDF revision compareText and image compared, only the changes highlighted, finished inside the browser 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 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 3D viewerOpen without installing, turn it around, triangle count and size Bundle mapwebpack, esbuild, heaviest paths, duplicate packages Find similar photosBurst shots, survives resize and recompression, 64-bit dHash, stays in your browser Photo locationsEXIF place and time, grouped by date, dots only, nothing leaves the browser Read aloudSentence splitting, time estimate, browser voices, nothing to install Call graphimport/require graph, cycles, entry points and dead files, no heavy parser My Writing AtlasNotes → terrain, peaks and valleys, buried notes, pairs to link, a control beside every 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