All tools
78 tools across 8 categories. Search by name, browse a category or use the alphabetical index.
Electronics 8
Resistors, Ohm's law, LEDs and wiring
- AWG wire gauge converterConvert American Wire Gauge sizes to wire diameter and cross-sectional area in metric or imperial units.
- Battery life calculatorEstimate battery runtime from capacity and current draw. Adjust usable capacity to compare scenarios.
- Ceramic capacitor decoderDecode three-digit capacitor markings and show the capacitance in picofarads, nanofarads and microfarads.
- LED series resistor calculatorCalculate an LED series resistor and its power dissipation from the supply voltage, forward voltage and current.
- Ohm's law calculatorEnter two circuit values to calculate voltage, current, resistance and power, with units and formulas.
- Parallel resistor calculatorCalculate total resistance for resistors in parallel or series. Add values and compare how current divides.
- Resistor color code calculatorRead a 4, 5 or 6 band resistor's value from its colors, or enter a resistance to find the matching bands.
- Voltage divider calculatorFind the output voltage of a two-resistor divider, or solve for either resistor value.
Developer 14
Format, encode, convert and compare
- Base64 encoder and decoderEncode text as Base64 or decode it back to text. Supports UTF-8 and URL-safe Base64.
- Cron expression generatorBuild a five-field cron schedule, read its meaning and preview the next run times.
- CSV and JSON converterConvert local CSV and JSON with quoted cells, preserved identifiers, column types and downloadable output.
- Image to Base64 converterConvert an image into a Base64 data URL, HTML image tag or CSS background. Preview it before copying the result.
- JavaScript regex testerTest patterns, inspect captured groups and preview replacements with a stoppable browser worker.
- JSON formatter and minifierValidate, format or minify JSON while preserving large numbers. Browse a source-aware tree, find keys and inspect duplicate-key warnings.
- Markdown to HTML converterWrite Markdown, preview the result and copy the HTML. Includes headings, lists, links, tables and code blocks.
- Number base converterConvert integers between binary, octal, decimal and hexadecimal, with a view of the individual bits.
- Secure password generatorGenerate random passwords or passphrases in your browser. Choose the length and character sets, then copy the result.
- String hash generatorCalculate MD5 and SHA hashes for text, or encode it as Base64. Compare and copy the results.
- Text diff checkerCompare two texts side by side or in a unified view. Highlight changed lines and words, with case and whitespace options.
- Unix timestamp converterConvert Unix timestamps in seconds or milliseconds to dates, or turn a date into a timestamp.
- URL inspector and encoderRead URL parts and raw query pairs, remove selected parameters, and encode or decode text with explicit rules.
- UUID generatorGenerate version 4 UUIDs individually or in batches. Inspect an existing UUID to check its version and structure.
Design 6
Color, layout and CSS helpers
- Aspect ratio calculatorFind an aspect ratio or calculate a missing width or height. Compare sizes for images, video and screens.
- Color contrast checkerCheck the contrast ratio between two colors and see which WCAG text and interface thresholds they meet.
- Color converterConvert between HEX, RGB, HSL and HSV. Preview the color and copy values for CSS.
- CSS box shadow generatorAdjust offset, blur, spread and color with a live preview. Combine layers and copy the CSS.
- Golden ratio calculatorDivide a length by the golden ratio, find related dimensions and preview the proportions.
- Lorem ipsum generatorGenerate placeholder words, sentences or paragraphs. Copy plain text or HTML for a layout.
Money 6
Loans, savings, tips and currency
- Compound interest calculatorCalculate growth from an initial balance, regular contributions and a fixed interest rate. Compare compounding schedules.
- Currency converterConvert currencies with daily exchange-rate data. Check the rate date and compare several amounts.
- Discount and sales tax calculatorCalculate stacked discounts, user-entered tax and final totals with a receipt breakdown and rounding choices.
- Mortgage payment calculatorEstimate fixed-rate mortgage payments and total interest. Include property tax, insurance and HOA fees if needed.
- Tip calculatorCalculate a tip, split the bill and see the total per person. Adjust the tip percentage and rounding.
- Unit price comparisonCompare multipack prices at the same quantity and see the cheapest offer with savings against your baseline.
Text and math 7
Reformat, count and check
- Case converterConvert text to sentence case, title case, uppercase, lowercase, camelCase, snake_case and other naming styles.
- Fraction calculatorAdd, subtract, multiply or divide exact fractions, mixed numbers and decimals with reduced results and steps.
- Percentage calculatorCalculate a percentage, a proportion, percent change or an adjusted value with readable steps.
- Prime number checkerCheck whether an integer is prime and find its factors. Supports large numbers and labels probable-prime results.
- Text cleanup and list organizerTrim, deduplicate, sort and reshape lists with an ordered recipe while keeping the original text available.
- Vowel counterCount vowels, consonants, words and characters as you type. Compare the frequency of each vowel.
- Word and character counterCount words, visible characters, bytes and selected text. Estimate reading time at your chosen speed.
Everyday 10
Bikes, music, maps and QR codes
- Bicycle chain length calculatorEstimate chain length from chainstay length and chainring sizes. See the length in inches and half-inch links.
- BMX gear calculatorCompare chainring and sprocket combinations, gear inches, rollout and speed at a given cadence.
- BPM tapperTap along with a song to measure beats per minute. Compare half-time and double-time tempos.
- Date, age and working daysCount calendar or working days, calculate age, and add days or months using your weekend and holiday rules.
- QR code generatorCreate QR codes for text, links, Wi-Fi and contact actions. Adjust colors and download PNG or SVG.
- QR code readerDecode a QR code from a local image. Inspect text, website links, Wi-Fi details or contact fields before choosing a copy or open action.
- Sunrise and sunset mapChoose a location and date to calculate sunrise, sunset, twilight and day length on a world map.
- Time zone meeting plannerCompare full local dates and times across zones and find slots that fit the working hours you enter.
- Tire pressure converterConvert tire pressure between PSI, bar and kPa. See all three units together.
- Unit converterConvert length, area, volume, mass, temperature, speed, pressure and data size with explicit unit definitions.
Files and images 7
Resize, inspect, convert and organize
- Image compressorCompress JPEG, PNG or WebP images locally. Set maximum dimensions or a target size, compare the result and download the measured output.
- Image format converterConvert still images between JPEG, PNG and WebP. Choose a transparency background, quality and optional maximum width.
- Image metadata viewer and cleanerInspect camera, date, GPS, EXIF, IPTC and XMP tags in a local image. Create a cleaned copy and verify its exported metadata.
- Image resizer and cropperCrop, rotate, flip and resize JPEG, PNG or WebP images. Use ratio presets or exact coordinates and export from the original pixels.
- Images to PDFArrange local images into a PDF. Choose paper size, orientation, margins, fit or fill, resolution and image quality before exporting.
- PDF page organizerMerge, reorder, rotate, duplicate or extract PDF pages locally. Copy original page content and download a PDF or separate-page ZIP.
- PDF to imagesRender selected PDF pages as PNG or JPEG images locally. Choose DPI or pixel width and download pages individually or as a ZIP.
Trades and industry 20
Measure materials, plan layouts and check geometry
- Baker's percentage and dough scalerScale a flour-basis formula by dough mass, flour mass or piece count, with preferment accounting and printable weigh-outs.
- Brick and block estimatorSubtract wall openings, include mortar joints and estimate whole units and packs with a visible waste allowance.
- Concrete volume and bag estimatorAdd slabs, footings and round piers to estimate concrete volume, whole bags and material cost from your product yield.
- Conduit offset calculatorCalculate ideal two-bend spacing and shrink, and compare them with your verified bender multipliers and mark references.
- DC cable voltage drop calculatorEstimate two-wire DC drop and power loss from a cable specification, measured loop resistance or supplied resistivity.
- Dilution and batch ratio calculatorCalculate concentrate and diluent amounts with explicit product-to-water or product-to-total ratios and matching volume concentration bases.
- Fabric yardage and repeat plannerEstimate roll length for rectangular fabric pieces with seam allowance, straight repeats, grain and nap restrictions.
- HVAC airflow and duct calculatorCalculate actual duct airflow, mean velocity or required area with clear metric and imperial units.
- Lumber board foot estimatorAdd a lumber list, keep actual and quoted dimensions separate, and calculate board feet, volume and cost.
- Machining speeds and feeds calculatorConvert supplied cutting speed and chip load into RPM and feed, then compare actual settings with entered machine limits.
- Mulch, soil and gravel estimatorTotal multiple beds or paths, separate compaction from purchasing allowance, and calculate whole bags or bulk volume.
- Paint coverage and can estimatorMeasure rooms and openings, then estimate finish paint and primer cans using your coverage, coats and allowance.
- Pallet layer and stack plannerCompare carton orientations on a pallet and calculate full layers under entered total height and gross mass limits.
- Pipe rolling offset calculatorCalculate true offset, travel, advance and roll angle, then enter actual fitting takeouts for a straight cut length.
- Print sheet yield and cut layoutPlan rectangular pieces per sheet with print margins, bleed, gaps and grain restrictions, then export the cut map.
- Pulley and belt drive calculatorCalculate ideal driven RPM, pitch-line speed and geometric open-belt length from pitch diameters and center distance.
- Roof pitch and rafter calculatorConvert roof pitch between rise/run, degrees and percent, and calculate common-rafter centerline and overhang geometry.
- Sheet metal bend allowanceCalculate one bend's allowance, setback, deduction and flat blank length using explicit outside-flange datums.
- Stair rise and run plannerCompare equal-riser layouts, choose the top landing and check tread dimensions against your entered constraints.
- Tile layout and cut plannerPreview a rectangular tile grid, compare centered layouts, inspect edge cuts and estimate whole boxes.
