Base58 encoder/decoderConvert UTF-8 text with the Bitcoin Base58 alphabet, preserving leading zero bytes.
Number-base converterConvert signed integers exactly between binary, octal, decimal and hexadecimal with BigInt.
ROT13 & Caesar cipherShift ASCII letters with a Caesar cipher or ROT13 while preserving other characters.
ZIP archive toolPack selected files into a ZIP archive or extract supported ZIP entries individually.
Bzip2 compressorCompress text or one file to Bzip2 and decompress local Bzip2 data using WebAssembly.
Zstandard compressorCompress text or files to Zstandard .zst and decompress standard Zstandard frames.
Character encoding converter and mojibake diagnosticsConvert UTF-8 and UTF-16 text/bytes, or inspect conservative recovery candidates for garbled text and original files locally.
Batch file renameAdd sequences, date prefixes or replace names, preview collisions and export ZIP copies.
File type inspectorIdentify likely formats and MIME by signature, check extensions and inspect hexadecimal headers.
Folder Comparison and Backup VerificationCompare relative paths and SHA-256 hashes of two local file sets, then export added, missing and modified entries as CSV or JSON.
AES encrypt and decryptEncrypt UTF-8 text with password-derived AES-256-GCM, or decrypt this tool’s envelope.
RSA encrypt and decryptGenerate a 2048-bit RSA-OAEP keypair and encrypt/decrypt short UTF-8 messages with SHA-256.
JWT decoder and signature verifierDecode JWT JSON and verify RS256, PS256 or ES256 signatures locally with a supplied public key; inspect claim checks separately.
UUID generatorGenerate secure UUID v4 or v7 batches and inspect UUID format, variant, version and supported timestamps locally.
SSL certificate and PEM bundle parserInspect local PEM bundles or a DER certificate: subjects, issuers, validity, public keys, fingerprints and candidate chain order.
JSON formatterFormat JSON with two-space indentation, compact it, or recursively sort object keys in your browser.
JSON repairRepair common JSON syntax problems locally, compare the exact text changes, and copy or download the reviewed result.
YAML formatterFormat supported YAML mappings, sequences and scalar values with consistent indentation.
JavaScript beautifierFormat JavaScript tokens with indentation while preserving line-sensitive boundaries.
JSON to TypeScript, Go, Python & RustInfer TypeScript, Go, Python and Rust types from JSON, with optional fields, null handling and number precision checks.
JSONPath queryQuery JSON with property paths, array indices and wildcards, returning path/value matches.
Markdown previewPreview Markdown and check local file links, heading anchors, duplicate IDs and undefined references within selected files.
Mermaid diagram previewRender Mermaid syntax as safe SVG diagrams locally in the browser with live preview
XPath query testerQuery local XML nodes, attributes and scalar values with an explicit namespace map and complete JSON export.
YAML/TOML structured comparisonCompare local YAML and TOML paths and values with integer, float and date types preserved.
Timestamp converterConvert Unix seconds or milliseconds to local date-time, or turn a local date-time into Unix seconds.
Date calculatorFind the signed number of calendar days between dates, or add and subtract days from a date.
Workday calculatorCount a custom Gregorian work calendar with selected weekly weekends, holiday and make-up dates, endpoint choices, a complete daily list and bounded CSV.
Current Unix timestampShow the current Unix seconds, milliseconds, local time, UTC, and ISO 8601 value from your device clock.
Time zone converterConvert local times in 13 IANA zones with explicit DST choices, then find common weekly working-hour meeting slots and prepare UTC ICS.
China public holidaysLook up China’s built-in 2024–2026 holiday periods and compensatory working days.
Chinese lunar calendarConvert a Gregorian date to Chinese lunar-calendar fields and the associated zodiac animal.
Chinese zodiac lookupFind the Chinese zodiac animal using a full birth date and its lunar-calendar year.
Date range checkerCheck whether a date falls inside an inclusive range and compare elapsed versus inclusive day counts.
Pomodoro timerAlternate focus sessions, short breaks, and scheduled long breaks with a configurable browser timer.
Cron Time Zone and DST SimulatorParse numeric five-field Cron with an IANA zone, explicit start and execution count; inspect skipped and repeated local times.
Cron expression generatorBuild five-field Cron expressions from minute, hourly, daily, weekly, monthly, or custom settings.
Weekday and day-of-yearFind a date’s weekday, Monday-based weekday number, and ordinal day within its year.
Relative timeCompare a local target date-time with the device’s current time using relative wording and an elapsed-time breakdown.
ISO week lookupConvert a calendar date to its ISO week-year, week number, weekday, and Monday-to-Sunday range.
Printable month and week plannerGenerate a Gregorian month grid, week planner or blank weekly timetable with local notes.
ICS calendar generator and inspectorGenerate local iCalendar from a JSON event array, or inspect a supported ICS profile, then preview occurrences, exclusions and overlaps.
List comparisonCompare two newline lists locally: intersection, A-only, B-only, union and symmetric difference, with exact identifiers and first-occurrence records.
String literal escape / unescapeEscape text or decode a restricted JSON, JavaScript or Python string literal locally, with ASCII previews and explicit quote and content-only modes.
Word counterCount Unicode code points, whitespace-separated words, lines and paragraphs. Word and phrase frequencies.
Find and replaceReplace literal text or JavaScript regex matches with optional case and global controls.
Unicode transliteratorTransliterate supported Latin, Greek and Cyrillic characters to Latin letter sequences.
Duplicate line removerRemove duplicate lines while retaining the first or last occurrence in source order.
Regex testerTest JavaScript regular expressions with match positions, capture groups and replacement preview.
Log sensitive data redactorDetect and replace emails, phone numbers, tokens, cookies, IP addresses, and connection strings locally in the browser
Lorem ipsum generatorGenerate randomized Latin-style or Chinese placeholder paragraphs for layout testing.
Chinese script converterConvert Chinese between simplified, traditional, Taiwan and Hong Kong variants with OpenCC.
Full-width / half-width converterConvert ASCII-width forms and U+FF01–U+FF5E full-width forms, with optional space conversion.
Text column alignerArrange successive text lines into aligned columns using estimated Unicode display widths.
Text shufflerShuffle characters, whitespace-separated words or lines with browser cryptographic randomness.
HTML tag removerExtract plain text from an HTML fragment, optionally preserving block breaks and removing script/style content.
Hidden character inspectorFind zero-width characters, unusual spaces, bidi controls and unpaired surrogates locally; review exact positions and remove only individually selected occurrences.
Unicode normalizationCompare original text with NFC, NFD, NFKC and NFKD locally, inspect code points and byte lengths, and download a reviewed form or complete escaped report.
Newline and UTF-8 BOM converterInspect mixed LF, CRLF and CR line endings locally, preserve the original, and export a reviewed UTF-8 file with an explicit BOM policy.
SRT / VTT subtitle converterA bounded SRT/WebVTT conversion subset. Preserve millisecond timings and multiline cue payloads literally, regenerate numbering, count overlaps, or extract text. No video playback, synchronization or complete format validation.
Subtitle timing correctionApply a signed millisecond offset or a two-anchor linear correction to the supported SRT/WebVTT subset. Preserve literal multiline payloads and preview before/after timings. No playback, speech matching, frame-rate detection or automatic alignment.
CSV viewer and cleanerPreview CSV or TSV, trim selected columns, replace empty values, normalize explicit date formats and remove duplicate or empty rows locally.
CSV key diffCompare CSV snapshots by primary or composite keys, diagnose duplicate keys and export added, removed and changed records.
CSV join and mergeJoin two CSV tables by mapped or composite keys with left, inner or full joins, explicit duplicate handling, selected columns and local CSV or JSON downloads.
CSV pivot and unpivotReshape CSV locally with multiple row keys, one column key and count, sum, average, minimum or maximum, or turn selected columns into long-form raw strings.
CSV split and mergeSplit CSV by data-row count or exact column value, or append local files with strict, aligned or union headers. Download bounded CSV and ZIP results locally.
Local SQL workbenchImport local CSV or flat JSON tables, query them with SQLite SELECT and WITH, join and aggregate rows, and export bounded CSV results in your browser.
Parquet viewer and converterOpen a local Parquet file, inspect supported flat schemas and typed rows, and export an inclusive row range as protected CSV or schema-aware JSON.
SQLite file viewerOpen a local SQLite database read-only, inspect schema and indexes, and export bounded table-row ranges as typed CSV or JSON without uploading the file.
Excel workbook diffCompare two local XLSX workbooks by cell address or exact composite keys, separating values, types, formulas, cached results and workbook structure.
JSON diff and JSON PatchCompare JSON values, inspect path differences and export a locally verified RFC 6902 JSON Patch without losing decimal precision.
CSV validator and data quality profilerValidate CSV or TSV structure and profile missing values, exact duplicates, likely types and optional numeric or date statistics locally.
JSON Lines converterConvert JSON Lines into a JSON array or split a JSON array into compact JSONL records.
CSV to Markdown tableConvert CSV or TSV rows into an escaped Markdown table with selectable alignment.
MessagePack / CBOR encoder and decoderEncode JSON or typed JSON, and inspect binary data locally without uploading it.
Fixed-width text to CSVSet character widths or end boundaries, inspect every cut, and export CSV locally. No uploads or stored inputs.
Product Feed validatorCheck required core fields, exact IDs, HTTP(S) URLs, ordinary-product prices and cross-field dates using one dated local profile for CSV and RSS 2.0 XML.
Image toolboxSwitch between image conversion, editing, recognition, batch processing, and generation in one place
Image compressorCompress images with manual quality or measured target-KB search across format, quality and dimension settings.
Image format converterConvert supported local HEIC/HEIF and raster images to PNG, JPEG, WebP or real AVIF.
AI Background RemoverRemove image backgrounds with an AI model running locally in your browser, then export transparent PNG or a solid color
Batch image processorBatch resize and convert supported HEIC/HEIF and local raster images, or generate responsive width and format variants with picture/srcset snippets and a ZIP.
Image collage and contact sheetCreate image collages or contact sheets with rectangular thumbnail grids, numbered captions or file-name labels, entirely locally.
Image OCR — English, Chinese and JapaneseRecognize printed English, Simplified Chinese or Japanese locally with a selected language model. Engine/model assets (about6–8 MiB per run) load from this site; your image is never uploaded. No remote OCR fallback.
PNG to ICOBuild a multi-size ICO or complete favicon ZIP with browser/touch PNG icons, webmanifest, HTML links and deployment notes.
Screenshot beautifierBeautify screenshots and redact sensitive regions with opaque black rectangles; verify covered pixels before downloading or copying PNG.
ID photo makerCreate one-inch, two-inch, passport, and custom ID photos locally with background color, positioning, optional AI cutout, and sheet export
Image to SVGWrap PNG, JPEG, and other images in an embeddable SVG locally with dimension and aspect-ratio controls
Meme / poster makerAdd meme captions or a poster information panel to an image locally, then copy or export PNG and JPEG
Images to PDFArrange local images into an A4 or Letter PDF with page order, orientation, margins, and fit options
Automatic Image Border CropDetect transparent or near-white borders, inspect crop bounds and export a local PNG with retained padding.
Image print preflightLocal PNG/JPEG header preflight: dimensions, print size and supported metadata. Compressed pixels and ICC profile contents are not decoded or validated; this does not certify image validity or print readiness.
Local duplicate image checkerCompare local static PNG and supported JPEG files. Exact groups require SHA-256 plus equal bytes; similar pairs are suggestions to inspect manually. Files are never deleted or uploaded.
Video contact sheetSample a local MP4 or WebM video at regular intervals and export a labeled PNG or single-page raster PDF. No upload; the example loads an authored video from this site.
Image pixel comparisonCompare same-size images with sliding views, overlays, difference heatmaps and pixel statistics.
Scan Deskew and CleanupManually rotate and deskew pages, whiten gray paper and adjust contrast, then preview color, grayscale or black-and-white scans and export PNG ZIP or PDF.
QR code generatorEnter text or a URL, choose the error-correction level, scale, and quiet zone, and generate a QR code.; includes CSV batch QR labels, A4 / thermal PDFs and ZIP.
Wi-Fi QR codeEncode an SSID, authentication mode, password, and hidden-network flag using the common Wi-Fi QR format.
vCard QR codeGenerate a vCard 3.0 QR code with name, phone, email, organization, website, and address fields.
Barcode generatorGenerate individual PNG/SVG barcodes or lay out bounded CSV batches as physical-size label PDFs with paper templates and calibration.; includes CSV batch QR labels, A4 / thermal PDFs and ZIP.
Styled QR codeCustomize foreground, background, and dot style while generating a QR code with a safe contrast and quiet zone.
QR image decoderUpload a local image and use the browser's BarcodeDetector to read QR content, reporting unsupported and undecoded states explicitly.
Barcode to textUpload a local image and use BarcodeDetector to read barcode text, with format selection and text download.
IP address calculatorCalculate an IPv4 subnet mask, network, broadcast address and usable host range from CIDR.
User-Agent parserInspect a user-agent string for browser, engine, OS, device class and bot-like markers.
URL parserInspect and edit URL components, or build campaign links from CSV with batch UTM parameters, collision checks and export.
Unicode character lookupInspect Unicode code points, UTF-8 bytes and UTF-16 escapes without a character-name database.
Regular expression libraryBrowse reusable regex examples with descriptions, flags and sample strings.
JSON Mock rule engineGenerate repeatable Mock JSON locally from field rules, types, ranges, and choices
Environment variable converterConvert .env and JSON, compare environment variables locally, and export a placeholder-only .env.example.
Cron expression readerExplain a five-field cron expression with a summary and per-field descriptions.
HTTP status code tableLook up HTTP response codes from 1xx to 5xx by number, English phrase or translated meaning.
Sitemap XML generatorBuild sitemap.xml from URL lines with optional modification dates, frequency and priority.
OpenAPI validator, diff and browserValidate, compare and browse OpenAPI locally, or convert OpenAPI and Postman 2.1 collections with explicit authentication, script and schema loss reports.
Protobuf encoder and decoderEncode schema-aware JSON to Protobuf, decode binary/Hex/Base64, and inspect wire fields locally
SQL Schema converter, ER and migration diffConvert SQL schemas, draw ER diagrams, compare two schemas and review dialect-specific migration drafts locally
GraphQL validator and formatterValidate SDL and GraphQL operations, fragments and variables locally; format documents and browse types
cURL to code converterConvert one cURL command locally into JavaScript Fetch, Python Requests, or Go net/http code, with explicit syntax limits and optional credential redaction.
Internationalization file checkerCompare locale JSON keys, types, placeholders and a declared flat ICU plural subset locally, with located issues and a complete JSON report.
HAR viewer & sanitizerInspect HAR requests, headers, bodies and timings locally, filter by domain or status, and export a configurable redacted archive for manual review.
HTTP response header analyzerParse pasted HTTP response headers locally, preserve repeated fields, and review caching, content type, redirects, CORS and security-header guidance.
Cookie / Set-Cookie parserInspect pasted Cookie request headers or Set-Cookie response headers locally, retain repeated entries and attributes, and export value-masked JSON by default.
Docker run to Compose converterConvert a supported Docker run command into Compose YAML locally, with environment values masked by default and explicit compatibility warnings.
Compose static validatorValidate Compose YAML locally against a pinned official schema and inspect located structure, service-reference and port diagnostics without running containers.
SemVer range testerTest a version list against npm SemVer ranges locally, with explicit prerelease matching, invalid-row detection and sorted matches that preserve build metadata.
package.json diffCompare dependency sections, scripts, engines and metadata in two package.json files locally, with clear moves and complete JSON export.
.gitignore rule testerTest one root .gitignore against sample paths locally, with ordered exceptions, excluded-parent explanations and matching rule lines.
chmod permission calculatorConvert octal and nine-character Unix permission strings locally, including setuid, setgid and sticky bits, with file and directory explanations.
JSON Schema validatorValidate JSON against Draft 7, 2019-09 or 2020-12 schemas locally, with local references, worker timeouts and paths-only diagnostics.
CSS Grid / Flex Layout GeneratorVisually set Grid columns or Flex direction, wrapping, gaps and alignment, then preview the layout and copy compact HTML/CSS.
Batch UTM link builderAdd campaign parameters from CSV, check existing UTM collisions and duplicate keys, preview every row and export safe CSV.
CSS shadow & radiusGenerate CSS shadows, borders, and rounded corners with live preview and two-layer presets
Scientific calculatorEvaluate arithmetic, powers, factorials, trigonometric functions, logarithms, and supported named functions.
BMI calculatorCalculate BMI from height in centimeters and weight in kilograms, with the tool’s displayed category bands.
Percentage calculatorCalculate percentage change, one value as a share of another, or a percentage of a value.
Unit converterConvert length, mass, area, volume, and fixed-duration time units using built-in factors.
Volume converterConvert liters, milliliters, cubic units, US cooking measures, and US or imperial gallons.
Data unit converterConvert bits, bytes, decimal KB–TB, and binary KiB–TiB while keeping the two prefix systems distinct.
Pressure converterConvert pressure among Pa, kPa, MPa, bar, atm, psi, mercury-column units, and kgf/cm².
Power converterConvert watts and scaled watt units, mechanical horsepower, metric horsepower, BTU/h, and kcal/h.
Fuel calculatorCalculate fuel use in L/100 km, efficiency in km/L, and trip fuel cost from distance and fuel consumed.
Mortgage calculatorEstimate mortgage payments and total interest using equal-payment or equal-principal repayment.
Loan calculatorEstimate a fixed-rate loan using equal-payment or equal-principal repayment over a specified number of months.
Tip calculatorCalculate tax, a tip on the tax-inclusive bill, the final total, and an equal per-person share.
Age calculatorCalculate calendar age in complete years, months, and days, plus total days and the next birthday.
Compound interest calculatorEstimate compound growth with an initial principal and equal contributions at the end of each compounding period.
Random number generatorGenerate random integers or fixed-decimal values inside an inclusive range, optionally without repeats.
Dice rollerRoll configurable virtual dice and inspect individual results, total, minimum, maximum, and average.
Unit price comparatorCompare compatible package quantities, multipacks, discounts and shipping with exact unit-price ranking.
Gross margin and markup calculatorCompare gross-margin and markup denominators, reverse a gross target price and separately estimate user-entered fees.
Break-even scenario calculatorCompare fixed costs, unit variable costs, prices and quantities with exact and whole-unit break-even thresholds.
Advertising metrics calculatorCalculate CPM, CPC, CTR, CPA, click-based CVR and ROAS; keep revenue separate from profit after entered costs.
Dimensional weight calculatorNormalize each box, round dimensions, calculate L × W × H / divisor, compare with actual weight, round the maximum, then multiply by quantity and sum.
Carton CBM calculatorConvert each carton’s three outside dimensions to meters, multiply length × width × height, then multiply by quantity and sum exact volumes.
SKU combination generatorGenerate the Cartesian product in entered order; the last attribute changes fastest. Preview the count before generation.
Weighted grades and target scoreEnter each category’s weight, earned score and maximum score. Choose explicit percentage weights or normalize positive relative weights. Pending work is separate from completed work.
Exact fractions with stepsCalculate two exact rational values. Enter an integer, a fraction a/b or a mixed number w n/d. A mixed number’s leading minus applies to the whole value: -2 1/3 means -(2 + 1/3).
Basic statisticsCompute descriptive statistics from a bounded list of decimal values. Choose population or sample variance and an explicit missing-value policy.
Printable arithmetic exercisesGenerate reproducible integer arithmetic exercises from the same seed and settings, with a separate answer page.
Screen rulerDisplay a horizontal or vertical CSS-pixel ruler with optional physical-unit calibration.
Post character counterCount story characters, Han characters, words, paragraphs, UTF-8 bytes and estimated reading time.
Recipe quantities and pan scalingScale ingredient fractions by servings or round, square and rectangular pan area or volume; convert compatible units and keep baking time separate.
Appliance energy and electricity costEstimate kWh and cost from your appliance watts, daily hours, days, duty cycle and entered flat electricity rate; inspect exact totals and export all rows.
CSV document generatorMerge exact CSV header placeholders into local name badges, certificates or notices, preview printable HTML and export documents with per-row reports.
PDF toolboxOrganize PDF pages and review likely blank pages with adjustable pixel thresholds, original previews and confirmed exclusions
Word to HTML / MarkdownConvert local DOCX to HTML or escaped Markdown with a ZIP of original local raster images
Invoice generatorKeep the receipt template and reuse goods to create clearly labeled quotations, packing lists and pro forma PDFs with exact totals and pagination.
PDF page and Bates numberingAdd sequential page or Bates labels to chosen PDF pages locally, with prefix, padding and rotation-aware placement.
PDF text or image watermarkAdd local text or PNG/JPEG watermarks to selected PDF pages, with transparency, nine positions, scaling, tilt and repeated stamps.
Crop PDF page marginsCrop PDF pages locally with per-page or selected-page top, right, bottom and left insets in pt, mm or inches. Preview and download a new PDF.
Unify PDF paper sizeConvert mixed PDF pages to A4, A3, A5, Letter, Legal or custom paper with proportional fit, shrink-only or original scale. Preview locally.
PDF multiple pages per sheetArrange 2, 4, 6 or 9 PDF pages per sheet locally. Choose paper orientation, row or column reading order, margins and gaps. Preview actual output.
PDF booklet impositionCreate booklet front/back spreads locally with left or right binding, optional blank padding and actual PDF previews.
PDF Form FillerFill supported AcroForm text, check boxes and preset choices locally; verify editable or flattened output.
PDF Bookmark EditorInspect and edit hierarchical PDF bookmarks locally; verify saved titles, page targets, order and open state.
PDF metadata inspectorInspect and edit supported PDF Info and XMP metadata locally, with saved-file readback and coverage limits.
PDF comparisonCompare two PDF versions locally with paired pages, overlays, pixel differences, optional extracted-text changes and JSON reports.
PDF embedded image extractorList unique indirect image XObjects in a local PDF, review supported image previews and dimensions, and export original JPEG bytes or decoded PNG images with a manifest in ZIP. Masks and unsupported objects are listed separately.
Office embedded image extractorInventory local DOCX/XLSX/PPTX image parts and package supported original raster bytes with generated names and a JSON inventory.
Searchable scanned PDFAdd a verified invisible English, Chinese or Japanese OCR layer to a local scanned PDF.
PDF table extractorExtract selectable text from one PDF page using a region and explicit column boundaries. Review the inferred cells before exporting. No upload or automatic OCR.
EML email viewerRead EML bodies, full headers and attachments locally and extract attachments without signing in.
VCF Contact Viewer and ConverterRead UTF-8 vCard 3.0/4.0 files in batches, inspect empty fields and duplicate candidates, then export selected contacts to CSV or original VCF cards.
Rock paper scissorsPlay rock paper scissors against the computer and keep a running win, loss, and draw record.
Number to ChineseConvert Arabic numerals to Chinese number words, including negative numbers and decimals.
Regex quizPractice regular expressions through five built-in challenges that test matching and rejecting sample strings.
Color memory gameMatch eight pairs of color cards while tracking the moves and time needed to complete the game.
Image to ASCII artConvert an image to copyable ASCII art in the browser, with character-width and invert controls.
Audio converter & waveform trimmerTrim audio, normalize linked sample peaks, add linear fades, preview and export locally as WAV, MP3, OGG Vorbis or supported AAC.
Idle timerListen for pointer, keyboard, wheel, and touch activity on the current page and measure the time since the last activity.