Built by a random guy on the internet.
For everyone who just needs the right tool.
Nivesly Tools is a free online toolbox — 100+ calculators, image converters, PDF tools, developer utilities, generators, and more. No paywalls, no account required, no dark patterns. Just tools that work, kept free by unobtrusive ads.
The honest origin story
I'm not a financial advisor. I'm not a doctor. I'm not a startup founder with venture capital and a marketing team. I'm just someone who spent way too many hours trying to find a decent mortgage calculator, only to land on sites that buried the result under pop-ups, required an email address, or were clearly designed to push you toward a lender.
So I built my own. Then I built more. The scope kept growing — financial calculators, health tools, image converters, a whole suite of PDF tools, password generators, developer utilities, color tools, regex testers, automotive calculators. Each one exists because I needed it and every existing version had something annoying about it.
That's Nivesly Tools. A side project from one person who thinks the internet deserves better, faster, cleaner tools — with no strings attached.
What Nivesly Tools actually covers
Over 100 free tools that run entirely in your browser — no accounts needed, and your data never leaves your device.
Financial Calculators
Mortgage, loan, auto loan, investment, retirement, compound interest, debt payoff, inflation, salary, budget, savings goal, expense splitter, sales tax, and more.
Health & Lifestyle Calculators
BMI, daily calorie needs, body fat percentage, and pregnancy due date calculator. Health data explained in plain language, not doctor-speak.
Automotive Calculators
Fuel cost, fuel economy, car depreciation, EV charging time, tire size, tire comparison, engine RPM, speedometer error, horsepower-to-weight, top speed estimator, towing capacity, wheel offset, brake pad life, oil change interval, and cost per mile.
Image Converters & Tools
Compress, crop, resize, rotate, and watermark images. Convert between JPG, PNG, WebP, HEIC, SVG, and PDF. Extract color palettes — all processed in your browser.
PDF Tools
Merge, split, rotate, reorder, extract, or delete PDF pages. Add watermarks, protect with a password, unlock PDFs, and edit PDF metadata — entirely in your browser.
Developer & Text Utilities
JSON formatter, JSON validator, Base64 encoder/decoder, URL encoder, hash generator, timestamp converter, regex tester, text diff, CSV↔JSON, slug generator, and more.
Text Tools
Word counter, character counter, text case converter, text sorter, remove duplicate lines, line break remover — fast clipboard-to-result utilities.
Generators
Secure password generator, strong password generator with entropy scoring, UUID v4 generator, QR code generator, Lorem Ipsum generator, random number generator.
Color Tools
Color picker, HEX↔RGB converter, RGB-to-HEX, gradient generator, contrast checker (WCAG AA/AAA), and color palette extractor from images.
Date & Age Tools
Age calculator and date-to-date calculator — find exact ages, count days between any two dates, and track deadlines.
What we stand for
- No dark patterns. Every result is shown immediately and completely. No forced email sign-ups to see your mortgage payment. No 'get a quote' redirects. Ads are present to keep the site free, but they never block your results.
- No made-up numbers. Every formula is documented and based on standard financial or clinical methodology. If we cite the 4% rule, the Mifflin-St Jeor equation, or the GVWR, that's actually what the calculator uses.
- Privacy by default. All calculations, image processing, and PDF operations happen entirely in your browser. Your financial figures, health data, uploaded files, and documents never leave your device. The server never touches them.
- Accessibility and speed. Every tool works on any device, any connection speed. No login walls. No account required. No bloated frameworks loading before you can type a single number.
- Honest limitations. Calculators produce estimates, not guarantees. A mortgage calculator gives you a payment estimate — not a lender's offer. We say so clearly. Nivesly Tools is a starting point, not a substitute for professional advice.
Who built this?
Just me — a random person on the internet with an interest in how useful tools should work and enough frustration with existing ones to actually do something about it.
I have no formal financial qualifications. I'm not a registered financial advisor, a CPA, a doctor, or a licensed anything. I'm someone who read enough books, spent enough time on financial and tech forums, and used enough bad tools to know what a good one looks like.
Nivesly Tools is a solo side project, built and maintained in spare time. It's not a company. It's not backed by investors. It doesn't have a sales team trying to upsell you into anything. It's just a growing collection of tools that I'm genuinely proud of.
If something is wrong, unclear, or could be better — let me know. I genuinely read and respond to feedback.
Want to support the project?
Nivesly Tools is free and will stay that way. Unobtrusive ads help cover hosting costs, but if you've found these tools genuinely useful and want to say thanks, you can buy me a coffee. It's optional, appreciated, and goes directly toward keeping the lights on and building more tools.
Important disclaimer
Everything on Nivesly Tools is for informational and educational purposes only. Nothing here constitutes financial, legal, medical, or investment advice. Calculator results are estimates based on the inputs you provide. Tool outputs — including image conversions, PDF operations, and generated content — are provided for personal, informational use. Always consult a licensed professional before making significant financial, health, or legal decisions.