Free online tools that run in your browser
37 calculators, converters, generators and file tools. Your files are opened, read and processed on your own device - they are never uploaded, so we cannot read them, store them, or lose them.
No sign-up No watermarks Works offline
- Bytes uploaded
- 0
- Files stored
- 0
- Accounts required
- 0
Every tool here does its work inside this tab. Open your browser’s network panel and use one - you will see nothing leave.
Most used
All 37 tools →-
Age calculator
Math & DatesFind an exact age in years, months and days from any date of birth, plus the total in weeks, days and hours and the countdown to the next birthday.
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BMI calculator
HealthCalculate body mass index from height and weight in metric or imperial units, see which WHO category it falls in, and get the healthy weight range for your height.
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cm to inches
ConvertersConvert centimetres to inches and back using the exact international factor, with a reference chart and the formula shown.
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Image compressor
ImageCompress images by quality or to a target file size, in batches, with the original never leaving your device.
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JSON formatter
DeveloperFormat, validate and minify JSON with precise error locations, optional key sorting and a structural summary of what the document contains.
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Mortgage calculator
FinanceWork out the full monthly cost of a home loan - principal, interest, tax, insurance and PMI - with a year-by-year amortisation schedule.
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Password generator
GeneratorsGenerate strong random passwords using your browser's cryptographic randomness, with entropy shown in bits and no password ever transmitted.
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PDF merge
PDFCombine any number of PDFs into one document in the order you choose, without uploading a single page.
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Word counter
TextCount words, characters, sentences and paragraphs as you type, with reading time, speaking time and the most-used words in your text.
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kg to lbs
ConvertersConvert kilograms to pounds and back with the exact international factor, plus a reference chart and stone conversions.
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Loan calculator
FinanceFind the monthly payment, total interest and full repayment schedule for any fixed-rate loan - car, personal, student or business.
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PDF split
PDFExtract specific pages, split into one file per page, or break a document into fixed-size chunks - without uploading it.
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Celsius to Fahrenheit
ConvertersConvert °C to °F and back with the formula shown, plus a reference chart of everyday and body temperatures.
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Compound interest calculator
FinanceSee how savings and investments grow over time, with regular contributions and any compounding frequency, plus a year-by-year balance table.
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Image converter
ImageConvert images between JPG, PNG, WebP and AVIF in batches, with quality control and transparency handled correctly.
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PDF compress
PDFShrink a PDF either losslessly, keeping text sharp and selectable, or aggressively by redrawing pages as images - with the trade-off stated plainly.
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QR code generator
GeneratorsCreate QR codes for links, Wi-Fi networks, email, phone and SMS. Download as PNG or SVG, with no watermark, no account and no expiry.
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Scientific calculator
Math & DatesA full scientific calculator with trigonometry, logarithms, powers, roots and factorials - type expressions directly or use the keypad.
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PDF to JPG
PDFTurn PDF pages into JPG or PNG images at any resolution, choosing which pages to convert, with everything rendered in your browser.
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Percentage calculator
FinanceWork out a percentage of a number, express one number as a percentage of another, or find the percentage increase or decrease between two values.
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Grade calculator
Math & DatesWork out your current weighted grade from assignments completed so far, and find the score you need on what remains to hit a target.
Browse by category
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Finance
4Mortgage, loan, interest and percentage maths with full schedules.
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Health
2Body mass index and daily energy needs, using published formulas.
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Math & Dates
5Scientific notation, ages, date spans, grades and GPA.
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Text
3Counting, case conversion and readability, without uploads.
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Generators
3Passwords, QR codes and random numbers from local entropy.
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Developer
5JSON, Base64, hashes, UUIDs and URL encoding.
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Image
6Compress, resize and change format without uploading photos.
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PDF
4Merge, split, shrink and export documents locally.
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Converters
5Length, weight and temperature with exact factors shown.
How processing in the browser works
When you drop a PDF into a typical online tool, the file is uploaded to a server, processed there, and sent back. That server has your document. How long it keeps it, who can read it and what happens in a breach are all questions you answer by reading a privacy policy and trusting it.
These tools work differently. The code that merges your PDF or compresses your photo is JavaScript and WebAssembly that runs inside your browser tab, using your own processor and memory. The file is read from disk by the browser, handled in memory, and written back out as a download. At no point is there a request carrying it anywhere.
That is not a claim you have to take on trust. Open your browser’s developer tools, switch to the Network tab, and use any tool on this site. You will see the page and its code load, and then nothing - no upload, whatever the size of your file.
What this changes in practice
- No size limits from us. There is no upload to cap. The only constraint is your device’s memory.
- No queue. Nothing waits on a shared server, so a busy afternoon does not slow you down.
- It works offline. Once a page has loaded, it keeps working with no connection at all.
- Confidential files stay confidential. Contracts, medical records and client work can be processed without a copy existing anywhere else.
What we do collect
Privacy-friendly, cookieless analytics that count page views and nothing else - no identifiers, no profiles, no cross-site tracking. If you accept the optional cookies, we additionally use Google Analytics to understand which tools are worth building next. You can change that choice at any time from the footer, and either way it never touches the files you process. Full detail is in the privacy policy.