Free tools for almost everything
Calculate, convert, generate, compress and create — instantly, with hundreds of free online tools.
Try: “Calculate my mortgage” · “Convert PDF to Word” · “Edit a PDF” · “Sign a document” · “Compress a PDF” · “Resize an image”
Popular tools
View all (332)- Mortgage CalculatorCalculate your home loan repayments, total interest and how much extra repayments could save you.Calculators
- Percentage CalculatorWork out X% of a number, what percentage one number is of another, percentage change and reverse percentages.Calculators
- PDF CompressorReduce PDF file size by recompressing images while keeping text sharp — free, private and in your browser.PDF & Documents
- Currency ConverterConvert between 150+ world currencies using regularly updated exchange rates.Converters
- QR Code GeneratorCreate free QR codes for links, text, Wi-Fi, email, phone, SMS and contact cards. Download PNG or SVG — no sign-up, no expiry.Generators
- Edit PDFEdit PDF files free in your browser: change existing text, add text, images and signatures, highlight, white-out, draw and redact.PDF & Documents
- Image CompressorCompress JPG, PNG and WebP images to make them much smaller — with a before/after preview and the size saved.Images
- Merge PDFCombine multiple PDFs into one file, in any order, choosing which pages to include from each.PDF & Documents
- Age CalculatorCalculate exact age in years, months and days from a date of birth — plus total days, weeks and your next birthday.Date & Time
- PDF to WordConvert PDF to an editable Word (.docx) document — keeps text formatting, headings, lists, tables and images. Free, private, in your browser.PDF & Documents
- GST / VAT CalculatorAdd or remove VAT, GST or sales tax at any rate — with the standard rate for 70 countries built in and your country selected automatically.Calculators
- Word CounterCount words, characters, sentences and paragraphs as you type, with reading time and keyword density.Text
Explore all tools
- 34 toolsCalculatorsPercentage, loan, mortgage, interest, salary, tax and everyday maths calculators.Mortgage Calculator · Percentage Calculator · Age Calculator · GST / VAT CalculatorExplore
- 124 toolsUnit & Currency ConvertersConvert length, weight, temperature, volume, speed, data, currency and more.Currency Converter · Celsius to Fahrenheit · Temperature Converter · Length ConverterExplore
- 30 toolsPDF & Document ToolsMerge, split, compress, rotate, convert, protect and edit PDF files.PDF Compressor · Edit PDF · Merge PDF · PDF to WordExplore
- 27 toolsImage ToolsCompress, resize, crop, convert and edit images in your browser.Image Compressor · Image Resizer · JPG to PDF · Background RemoverExplore
- 29 toolsText ToolsCount words, change case, clean, sort, compare and transform text.Word Counter · JSON Formatter & Beautifier · PDF & Image OCR · Case ConverterExplore
- 38 toolsDeveloper ToolsFormat and validate JSON, XML, SQL; encode, decode, hash and convert data.JSON Formatter & Beautifier · Password Generator · JSON Validator · Unix Timestamp ConverterExplore
- 15 toolsQR Codes & GeneratorsQR codes, passwords, random numbers, usernames, UUIDs and test data.QR Code Generator · Password Generator · Random Number Generator · Wi-Fi QR Code GeneratorExplore
- 16 toolsBusiness ToolsInvoices, quotes, receipts, margins, break-even, pricing and business documents.Invoice Generator · Profit Margin Calculator · ROI Calculator · Business Name GeneratorExplore
- 13 toolsSocial Media ToolsCaptions, hashtags, post templates, bios, image sizes and character limits.Instagram Caption Generator · Hashtag Generator · YouTube Title Generator · Social Media Image ResizerExplore
- 18 toolsDate & Time ToolsAge, date differences, working days, time zones, timers and clocks.Age Calculator · Days Between Dates Calculator · Date Calculator (Add or Subtract Days) · Time Zone ConverterExplore
- 20 toolsHome & Life CalculatorsPaint, flooring, tiles, concrete, garden, energy, fuel, travel and cooking.Mortgage Calculator · Mortgage Affordability Calculator · Stamp Duty Calculator · Fuel Cost CalculatorExplore
- 17 toolsSEO & Website ToolsMeta tags, Open Graph, robots.txt, sitemaps, schema markup and site checks.QR Code Generator · Word Counter · Meta Tag Generator · HTML FormatterExplore
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Why KitWren?
Completely free
Every tool is free to use. No trials, no paywalls, no watermarks on your files.
Fast
Pages load quickly and most tools give answers as you type.
Private by design
Many tools run entirely in your browser, so your files and data never leave your device.
Works on mobile
Designed for phones first, with big buttons and layouts that fit one hand.
No account needed
Open a tool, use it, leave. Favourites and history are kept in your browser.
Made for everywhere
Metric and imperial units, 150+ currencies, world time zones and international formats.
More popular tools
- Income Tax CalculatorEstimate income tax and take-home pay for Australia, the UK, the US and New Zealand using current rates.Calculators
- Sign PDFSign a PDF online for free: draw, type or upload your signature, add initials and the date, and download the signed PDF.PDF & Documents
- Image ResizerResize images to exact pixel dimensions or by percentage, keeping the proportions if you like.Images
- JSON Formatter & BeautifierFormat, beautify and pretty-print JSON with your choice of indentation, and pinpoint syntax errors.Developer
- Invoice GeneratorCreate professional invoices with your logo, tax and payment details, then download a PDF — free, no sign-up.Business
- Password GeneratorCreate strong, random passwords or memorable passphrases, with a strength meter — generated on your device.Generators
- Compound Interest CalculatorSee how savings grow with compound interest and regular contributions, with a year-by-year table.Calculators
- Loan CalculatorCalculate repayments, total interest and the full cost of a personal loan, including fees.Calculators
- Days Between Dates CalculatorCount the days, weeks, months and years between two dates, with weekdays and an option to include the end date.Date & Time
Free online tools for everyday tasks
KitWren brings hundreds of free online tools together in one place, so you don’t need to hunt across different websites every time you need to work something out. Search for what you want to do in plain words — “how much will my repayments be”, “make this photo smaller” — and go straight to the right tool.
Calculators and converters
Our calculators cover percentages, GST and VAT, discounts, loans, mortgages, compound interest, salaries and tax, with the formula and a worked explanation on every page. The unit and currency converters handle metric and imperial measurements, temperatures, cooking measures, shoe and clothing sizes and more than 150 currencies.
PDF, image and document tools
Merge, split, compress and convert files with the PDF tools, and compress, resize, crop and convert photos with the image tools. Most of them run in your browser, so your documents and photos are processed on your own device rather than uploaded.
Developer, business and AI tools
Developer tools format and validate JSON, XML and SQL, encode and decode data, and generate hashes and UUIDs. Business tools create invoices, quotes and receipts and work out margins and break-even points, while AI tools help draft, rewrite and summarise text when you want a head start.