About UtilLab
UtilLab is a free online platform that brings together practical tools for everyday tasks: unit conversion, text formatting, scientific calculations, date arithmetic, and more. It was built for students, developers, writers, engineers, and anyone who needs a quick and reliable answer without installing software or creating an account.
Almost every tool on UtilLab runs entirely in your browser: what you type is not sent to a server and nothing is kept after you close the tab. The exceptions are the features that need a server, text to speech and the AI writing tools, which are explained in the Privacy Policy. The platform is designed to be fast and accessible on any device, whether you are working from a desktop, tablet or phone.
Why UtilLab exists
UtilLab started as a personal workbench: a handful of small tools we kept needing and kept re-finding across cluttered, ad-heavy websites. Instead of bookmarking ten different pages, we built one clean set of tools that loads fast, works on a phone and asks for nothing in return.
Every tool follows one rule: show the answer, but also show the reasoning. That is why converters display the conversion factor and reference tables, the financial calculators show a year-by-year breakdown, and each page carries a short guide that explains the method, its limits and the mistakes people commonly make.
What we stand for
- 01
Private by design
Calculations run in your browser. The text, numbers and passwords you type are never sent to our servers.
- 02
Accurate and transparent
We rely on published standards and well-tested libraries, and we say so on the page when a tool simplifies reality.
- 03
Fast and accessible
Light pages, keyboard shortcuts, readable contrast, a dark theme and a layout that works on any screen size.
- 04
Multilingual
The interface and the guides are available in several languages, with number, date and currency formats that follow each one.
How we keep the numbers right
Unit conversions use the exact factors from international definitions (the SI brochure from the BIPM, NIST Handbook 44 and the 1959 international yard and pound agreement) through the open-source convert-units library. Expressions in the scientific calculator are evaluated by math.js. Financial and date formulas are the standard textbook ones, and they are written out on each page so you can verify them by hand.
If you spot a mistake, tell us. Corrections are published as soon as they are verified.
What you can do here
- Text to SpeechNatural voices, subtitles and multi-voice dialogues, with AI.
- AI Video MakerVideos and quick ads from a topic: script, voice, subtitles and scenes.
- Unit ConverterConvert kilometers to miles, Celsius to Fahrenheit, and more.
- Currency ConverterConvert between 70+ currencies at daily rates: ECB reference rates plus market rates for the rest.
- Percentage CalculatorFind what percent of a number is, what percentage one value is of another, or calculate percentage change instantly.
- Compress ImageSmaller JPG, PNG and WebP files with adjustable quality.
- Merge PDFCombine several PDFs into one, in any order.
- Days Between DatesCount the days, weeks, months and business days between any two dates.
- Age CalculatorFind your exact age in years, months and days, and the countdown to your next birthday.
- QR Code GeneratorCreate QR codes for links, text, Wi-Fi, e-mail, phone and WhatsApp. Download PNG or SVG.
- Password GeneratorGenerate strong, random passwords using your browser's cryptographic API. Choose length and character types.
- Word CounterCount words, characters, sentences and reading time, and check social media and SEO limits.
- BMI CalculatorCalculate your Body Mass Index in metric or imperial units and see your weight category instantly.
- Discount CalculatorFind the sale price and how much you save, with one or two discounts, or work back to the original price.
- Image ConverterPNG, JPG and WebP in any direction, in bulk.
- Rule of ThreeSolve direct and inverse proportions step by step.
- JSON FormatterFormat, minify and validate JSON and find syntax errors by line and column.
- Convert CaseQuickly change your text between various formats: all uppercase, all lowercase, etc. Take advantage of our character, sentence, paragraph, and line counters.
- Advanced CalculatorPerform complex calculations with scientific functions and calculation history.
- Simple Interest CalculatorCalculate simple interest per month or per year for loans and investments.
- Compound Interest CalculatorSimulate how your money grows over time with compound interest.
- Date CalculatorFind out what date it will be in the future or what date it was in the past. Perfect for planning and scheduling.
- Password Leak CheckerCheck if a password appeared in data breaches without sending it, plus a strength estimate.
- Base64 EncoderEncode text to Base64 or decode it back, with full UTF-8 and URL-safe support.
- URL EncoderPercent-encode or decode URLs and query strings safely, for a component or a full URL.
- UUID GeneratorGenerate random v4 or time-ordered v7 UUIDs, one or in bulk.
- Hash GeneratorCompute MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any text and compare them.
- Unix TimestampEpoch time to a date and back, in seconds or milliseconds.
- Color ConverterHEX, RGB, HSL, CMYK and OKLCH with WCAG contrast.
- Regex TesterTest regular expressions with highlighted matches and groups.
- Text CompareSee what changed between two texts, by line or word.
- AI SummarizerSummarize texts and PDFs in seconds with AI.
- Paraphrasing ToolRewrite a text with other words, keeping the meaning.
- Grammar CheckerFix spelling, grammar and punctuation with AI.
- Tone ChangerMake a text formal, friendly, persuasive or simple.
- Split PDFExtract, delete or rotate pages, or split into single pages.
- Images to PDFJPG, PNG and WebP images into one PDF.
- Ad MakerA sale post, property or job ad with your photo, ready to download.
- Resize ImageExact pixels or a percentage, proportions kept.
- Crypto PricesBitcoin, Ethereum and the top 20 cryptocurrencies in your currency, with change and charts.
- Tip CalculatorWork out the tip and split the bill between any number of people.
- Statistics CalculatorMean, median, mode, standard deviation, variance and quartiles for a list of numbers.
- Time Zone ConverterConvert a date and time between world time zones, with daylight saving handled for you.
- Average CalculatorSimple and weighted averages and the grade you need to pass.
- Day of the WeekWhich day of the week any date falls on, with the ISO week.
- Public HolidaysPublic holidays of 200+ countries with weekdays, long weekends and regional days off.
How UtilLab is funded
UtilLab is free to use. To cover hosting and development we may display ads served by Google AdSense. Ads are kept separate from the tools and never influence results. Details about cookies and how to manage your ad preferences are in the Privacy Policy.
Contact
Questions, corrections or an idea for a new tool? Write to us at [email protected].