Free online tools for everyday work
Answer: Search or browse free calculators, converters, PDF & image utilities, text tools, and color tools — no signup, mobile-first, results you can copy instantly.
Start with Popular tools below, filter by category, or type what you need (“tip”, “compress image”, “mortgage”).
Popular tools
Count words, characters, sentences, and reading time instantly.
Open tool →BMI CalculatorBody Mass Index for US (lb/in) and metric — with category.
Open tool →Mortgage CalculatorUS home loan monthly payment — principal, interest, taxes & insurance.
Open tool →Age CalculatorExact age in years, months, and days from your date of birth.
Open tool →Sales Tax CalculatorAdd or remove US sales tax from a price in seconds.
Open tool →Hourly to Salary CalculatorConvert hourly wage ↔ annual salary (US work year).
Open tool →Tip CalculatorSplit bills and tip like in the USA & UK — per person totals.
Open tool →Percentage CalculatorWhat is X% of Y, percentage change, increase and decrease.
Open tool →Discount CalculatorSale price, % off, and how much you save.
Open tool →Date Difference CalculatorDays between two dates — weeks, months, and years.
Open tool →QR Code GeneratorCreate downloadable QR codes for URLs, Wi-Fi, and text.
Open tool →Password GeneratorStrong random passwords with length and character controls.
Open tool →New tools
Least common multiple with step-by-step work shown.
Open tool →TDEE CalculatorTotal Daily Energy Expenditure + cut/maintain/bulk targets.
Open tool →Federal Income Tax Calculator2026 IRS brackets + standard deductions. Federal tax estimate.
Open tool →Fancy Text Generator20+ Unicode font styles for Instagram, TikTok & Discord.
Open tool →Final Grade CalculatorWhat score do you need on your final? Plus full grade mode.
Open tool →GCF CalculatorGreatest common factor with step-by-step Euclidean work.
Open tool →Body Fat CalculatorBody fat % via the U.S. Navy tape-measure method.
Open tool →CD APY CalculatorProject CD growth with APY compounding.
Open tool →Volume CalculatorVolumes for sphere, cone, cylinder, cube & more + formulas.
Open tool →AI Token CounterEstimate LLM tokens + GPT/Claude/Gemini API cost.
Open tool →Citation GeneratorAPA, MLA & Chicago citations for books, sites & journals.
Open tool →Love CalculatorPlayful compatibility score for two names. Just for fun!
Open tool →Invoice GeneratorProfessional invoices with live totals — print/PDF export.
Open tool →Heart Rate Zone Calculator5 training zones with the Karvonen formula.
Open tool →Mean Median Mode CalculatorMean, median, mode, range & count — with sorted list.
Open tool →Image CompressorCompress JPG, PNG & WebP online — smaller files for email, WhatsApp & web.
Open tool →Time Zone ConverterConvert meeting times across USA, UK, and world cities.
Open tool →Currency ConverterConvert USD, GBP, EUR, PKR, AED and more with live rates.
Open tool →WhatsApp Link GeneratorCreate a wa.me click-to-chat link with a pre-filled message.
Open tool →Merge PDFCombine multiple PDF files into one.
Open tool →Split PDFExtract a page range from a PDF.
Open tool →Compress PDFOptimize and shrink PDF file size.
Open tool →JPG to PDFConvert images into a multi-page PDF.
Open tool →Reorder PDF PagesMerge PDFs in a custom file order.
Open tool →Rotate PDFRotate all pages 90°, 180°, or 270°.
Open tool →Ecommerce Profit CalculatorAmazon, eBay & Daraz product P&L — fees, ads, shipping, margin, ROI, break-even.
Open tool →Amazon Profit CalculatorAmazon FBA & FBM profit, referral fees, break-even & ROI.
Open tool →Browse by category
Discounts, tax, loans, salary, currency
Open category →Date & TimeAge, countdowns, time zones, durations
Open category →Unit ConvertersLength, weight, volume, storage, speed
Open category →Text ToolsWord count, case, clean, sort
Open category →Image ToolsResize, compress, convert
Open category →PDF ToolsMerge, split, compress
Open category →Developer ToolsJSON, Base64, UUID, regex
Open category →Design ToolsColors, gradients, CSS helpers
Open category →Security & GeneratorsPasswords, QR, random tokens
Open category →Productivity & DailyBMI, GPA, calories, random pickers
Open category →Color PlatformPicker, converter, palettes, contrast, gradients
Open color tools →All live tools (249)
Count words, characters, sentences, and reading time instantly.
Open tool →BMI CalculatorBody Mass Index for US (lb/in) and metric — with category.
Open tool →Mortgage CalculatorUS home loan monthly payment — principal, interest, taxes & insurance.
Open tool →Age CalculatorExact age in years, months, and days from your date of birth.
Open tool →Sales Tax CalculatorAdd or remove US sales tax from a price in seconds.
Open tool →Hourly to Salary CalculatorConvert hourly wage ↔ annual salary (US work year).
Open tool →Tip CalculatorSplit bills and tip like in the USA & UK — per person totals.
Open tool →Percentage CalculatorWhat is X% of Y, percentage change, increase and decrease.
Open tool →Discount CalculatorSale price, % off, and how much you save.
Open tool →Date Difference CalculatorDays between two dates — weeks, months, and years.
Open tool →QR Code GeneratorCreate downloadable QR codes for URLs, Wi-Fi, and text.
Open tool →Password GeneratorStrong random passwords with length and character controls.
Open tool →Text Case ConverterUPPER, lower, Title Case, Sentence case — one click.
Open tool →Compound Interest CalculatorGrowth of savings or investments with compounding.
Open tool →Loan / EMI CalculatorMonthly payment, total interest, and loan cost in seconds.
Open tool →Unit ConverterLength, weight, temperature, volume, speed, and digital storage.
Open tool →Image ResizerResize images by pixels or percent — download PNG/JPEG in-browser.
Open tool →Image CompressorCompress JPG, PNG & WebP online — smaller files for email, WhatsApp & web.
Open tool →Time Zone ConverterConvert meeting times across USA, UK, and world cities.
Open tool →Currency ConverterConvert USD, GBP, EUR, PKR, AED and more with live rates.
Open tool →WhatsApp Link GeneratorCreate a wa.me click-to-chat link with a pre-filled message.
Open tool →Percentage Increase CalculatorIncrease a number by a percentage instantly.
Open tool →Percentage Decrease CalculatorDecrease a number by a percentage instantly.
Open tool →Profit CalculatorCalculate profit from cost and selling price.
Open tool →Profit Margin CalculatorMargin % from cost and revenue.
Open tool →Markup CalculatorMarkup % from cost and selling price.
Open tool →ROI CalculatorReturn on investment percentage.
Open tool →Simple Interest CalculatorSimple interest on principal, rate, and time.
Open tool →Commission CalculatorSales commission from amount and rate.
Open tool →VAT CalculatorAdd or reverse UK-style VAT from a price.
Open tool →GST CalculatorAdd GST to a price at any rate.
Open tool →Average CalculatorMean of a list of numbers.
Open tool →PX to REM ConverterConvert CSS pixels to rem units.
Open tool →Aspect Ratio CalculatorSimplify width × height to a ratio.
Open tool →Color Picker & Palette StudioFree color picker: HEX, RGB, HSL, CMYK codes, shades, harmonies, WCAG contrast and palette export.
Open tool →URL Slug GeneratorTurn titles into SEO-friendly URL slugs.
Open tool →Remove Extra SpacesCollapse repeated whitespace in text.
Open tool →SEO + AEO + GEO — how we structure these pages
- SEO: unique titles, meta descriptions, canonicals, sitemap, breadcrumbs, fast static HTML.
- AEO: direct “Answer:” blocks and FAQ for featured snippets / AI Overviews.
- GEO: llms.txt, clear entity facts, and cite-ready definitions for ChatGPT, Perplexity, and Claude.
Learn who we are on the About page — important for E-E-A-T and AI citations.
FAQ
What free tools does KDF Tech offer?
KDF Tech offers 90+ free browser tools across finance, converters, date/time, text, image, PDF, developer, security, productivity, and color — including mortgage, tip, percentage, BMI, currency, QR, password, PDF merge/compress, and image compress/resize.
Are KDF Tech tools free for USA, Canada, and UK users?
Yes. All tools at kdftek.com/tools/ are free, require no signup, and run in the browser for users in the USA, Canada, UK, Australia, Europe, and worldwide.
Does KDF Tech build custom software as well?
KDF Tech is a software development company that builds Flutter mobile apps, Shopify storefronts, POS/ERP systems, and 6Valley/6amMart customizations for clients in the USA, UK, Pakistan, and worldwide. We also publish free daily online tools at kdftek.com/tools/.
Do these tools store my data?
No. Calculations and generators run locally in your browser. KDF Tech does not upload your tool inputs to our servers for these utilities.