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🔒 Private · in-browser tools

Fast, private, no-nonsense online tools

A growing collection of fast online tools and calculators. File tools run entirely in your browser — your files never leave your device.

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114 tools · no signup · files never leave your device

PrivateFile tools run in your browser
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100% freeEvery tool, no limits
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AllText & Developer ToolsImage ToolsPDF ToolsGeneratorsDate & TimeConvertersFinance CalculatorsIndia CalculatorsHealth & Fitness

Popular tools

Image Compressor

Shrink JPG, PNG and WebP file sizes in your browser without uploading. Adjust quality and download instantly.

Private · in-browser

Merge PDF

Combine multiple PDFs into one file, right in your browser. Reorder before merging; nothing is uploaded.

Private · in-browser

Word & Character Counter

Count words, characters, sentences, paragraphs and lines instantly. Runs entirely in your browser — your text never leaves your device.

Private · in-browser

JSON Formatter & Validator

Pretty-print, minify and validate JSON with clear error messages — entirely in your browser.

Private · in-browser

QR Code Generator

Create QR codes for URLs, text, Wi-Fi and contacts in your browser and download as PNG.

Private · in-browser

Password Generator

Generate strong, random passwords with custom length and character sets — in your browser.

Private · in-browser

BMI Calculator

Calculate your Body Mass Index and see your weight category instantly.

Private · in-browser

Percentage Calculator

Work out percentages: X% of Y, what percent one number is of another, and percentage change.

Private · in-browser

Text & Developer Tools

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Word & Character Counter

Count words, characters, sentences, paragraphs and lines instantly. Runs entirely in your browser — your text never leaves your device.

Private · in-browser

Case Converter

Convert text between UPPERCASE, lowercase, Title Case, camelCase, snake_case, kebab-case and more — instantly in your browser.

Private · in-browser

Slug Generator

Turn any title into a clean, URL-friendly slug. Removes accents and punctuation; runs in your browser.

Private · in-browser

Text Reverser

Reverse any string character by character. Handles Unicode correctly; runs locally.

Private · in-browser

Remove Duplicate Lines

Strip duplicate lines from a list, keeping the first occurrence. Optional case-insensitive and trim modes.

Private · in-browser

Sort Lines

Sort lines alphabetically, ascending or descending, with optional case-insensitive comparison.

Private · in-browser

Number Base Converter

Convert numbers between binary, octal, decimal and hexadecimal (or any base 2–36).

Private · in-browser

Roman Numeral Converter

Convert numbers to Roman numerals and back (1–3999), instantly in your browser.

Private · in-browser

Base64 Encode / Decode

Encode text to Base64 or decode Base64 back to text (UTF-8 safe), entirely in your browser.

Private · in-browser

URL Encode / Decode

Percent-encode text for safe use in URLs, or decode encoded URLs back to text.

Private · in-browser

HTML Encode / Decode

Escape HTML special characters (&, <, >, ", ') or decode entities back to text.

Private · in-browser

Epoch / Unix Timestamp Converter

Convert Unix timestamps (seconds or milliseconds) to human-readable UTC dates and back.

Private · in-browser

JWT Decoder

Decode a JSON Web Token to inspect its header and payload. Decoding only — no verification, all in your browser.

Private · in-browser

JSON Formatter & Validator

Pretty-print, minify and validate JSON with clear error messages — entirely in your browser.

Private · in-browser

JSON ↔ CSV Converter

Convert between JSON arrays and CSV in your browser. Handles nested keys and quoting.

Private · in-browser

XML Formatter

Pretty-print and indent XML for readability, locally in your browser.

Private · in-browser

YAML ↔ JSON Converter

Convert YAML to JSON and back, right in your browser.

Private · in-browser

Diff Checker

Compare two blocks of text and highlight the differences line by line.

Private · in-browser

Regex Tester

Test regular expressions against sample text with live match highlighting and flags.

Private · in-browser

Lorem Ipsum Generator

Generate placeholder lorem ipsum text by words, sentences or paragraphs.

Private · in-browser

Hash Generator (SHA-1 / SHA-256 / SHA-384 / SHA-512)

Generate cryptographic hashes of text using the browser’s Web Crypto API. Nothing is uploaded.

Private · in-browser

Markdown Preview

Write Markdown and see a live HTML preview, rendered safely in your browser.

Private · in-browser

Find & Replace

Find and replace text with optional case-insensitive and regex modes, all in your browser.

Private · in-browser

Cron Expression Parser

Explain a cron expression in plain English and preview its schedule.

Private · in-browser

UUID Generator

Generate random v4 UUIDs in your browser, one or many at a time.

Private · in-browser

Image Tools

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Image Resizer

Resize images to exact dimensions or by percentage, with optional aspect-ratio lock. Runs entirely in your browser — images never leave your device.

Private · in-browser

Image Compressor

Shrink JPG, PNG and WebP file sizes in your browser without uploading. Adjust quality and download instantly.

Private · in-browser

Bulk Image Compressor

Compress many images at once, entirely on your device. Pick a quality and download them all.

Private · in-browser

Image Converter (PNG / JPG / WebP / AVIF)

Convert images between PNG, JPG, WebP and AVIF locally — no upload, no quality sent to a server.

Private · in-browser

Image Cropper

Crop images to a custom selection or aspect ratio in your browser. Download the cropped result.

Private · in-browser

Image Rotator & Flipper

Rotate or flip images by 90° increments locally and download the result instantly.

Private · in-browser

Image to Base64

Convert an image to a Base64 data URL in your browser — handy for embedding in CSS or HTML.

Private · in-browser

EXIF Viewer

Inspect the EXIF metadata (camera, date, GPS) stored in a photo — read entirely on your device.

Private · in-browser

EXIF Remover

Strip EXIF and location metadata from photos for privacy, locally in your browser.

Private · in-browser

Image Color Extractor

Extract the dominant colors and palette from an image in your browser.

Private · in-browser

Image Watermark

Add a text watermark to images locally and download the result. Nothing is uploaded.

Private · in-browser

Image to PDF

Combine one or more images into a single PDF in your browser. Files never leave your device.

Private · in-browser

PDF Tools

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Merge PDF

Combine multiple PDFs into one file, right in your browser. Reorder before merging; nothing is uploaded.

Private · in-browser

Split PDF

Split a PDF into individual pages or ranges locally and download the parts.

Private · in-browser

Compress PDF

Reduce PDF file size in your browser by rebuilding the document. No upload required.

Private · in-browser

PDF to Image

Convert PDF pages to PNG images locally using pdf.js. Each page becomes a downloadable image.

Private · in-browser

Rotate PDF

Rotate all or selected PDF pages by 90° in your browser and download the result.

Private · in-browser

Reorder & Delete PDF Pages

Reorder or remove pages from a PDF locally, then download the rebuilt document.

Private · in-browser

Extract PDF Pages

Pull selected pages out of a PDF into a new file, entirely in your browser.

Private · in-browser

Add Watermark to PDF

Stamp a text watermark across every page of a PDF locally and download the result.

Private · in-browser

Add Password to PDF

Encrypt a PDF with a password in your browser so only people with the password can open it.

Private · in-browser

Remove PDF Password

Remove a known password from a PDF you can already open, locally in your browser.

Private · in-browser

PDF to Text

Extract the text content from a PDF in your browser using pdf.js. Copy or download as plain text.

Private · in-browser

Generators

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Percentage Calculator

Work out percentages: X% of Y, what percent one number is of another, and percentage change.

Private · in-browser

Color Converter (HEX / RGB / HSL)

Convert colors between HEX, RGB and HSL and preview the result.

Private · in-browser

Color Contrast Checker

Check the contrast ratio between two colors against WCAG AA and AAA standards.

Private · in-browser

QR Code Generator

Create QR codes for URLs, text, Wi-Fi and contacts in your browser and download as PNG.

Private · in-browser

Barcode Generator

Generate Code128, EAN and UPC barcodes locally and download as an image.

Private · in-browser

Password Generator

Generate strong, random passwords with custom length and character sets — in your browser.

Private · in-browser

Passphrase Generator

Create memorable, secure passphrases from random words.

Private · in-browser

Random Number Generator

Generate random numbers in a range, with optional uniqueness, using secure randomness.

Private · in-browser

CSS Gradient Generator

Design CSS gradients visually and copy the code.

Private · in-browser

Date & Time

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Date Difference Calculator

Find the number of days, weeks, months and years between two dates.

Private · in-browser

Date Add / Subtract

Add or subtract days, weeks, months or years from a date.

Private · in-browser

Age Calculator

Calculate exact age in years, months and days from a birth date.

Private · in-browser

Time Zone Converter & World Clock

Convert a time between time zones and see a world clock.

Private · in-browser

Stopwatch & Timer

A simple, accurate stopwatch and countdown timer that runs in your browser.

Private · in-browser

Converters

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Unit Converter

Convert length, mass, volume, area, speed, data, time and temperature units instantly.

Private · in-browser

Currency Converter

Convert between world currencies using live exchange rates.

Private · in-browser

Finance Calculators

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Loan / EMI Calculator

Calculate your monthly loan payment (EMI), total interest and payoff for any loan amount, rate and term.

Private · in-browser

Mortgage Calculator

Estimate your monthly mortgage payment, total interest and total cost over the life of the loan.

Private · in-browser

Auto Loan Calculator

Work out your car loan’s monthly payment and total interest by amount, rate and term.

Private · in-browser

Personal Loan Calculator

Calculate monthly payments and total cost for a personal loan.

Private · in-browser

Student Loan Calculator

Estimate student loan monthly payments and total interest over the repayment term.

Private · in-browser

Compound Interest Calculator

See how investments grow with compound interest and optional regular contributions.

Private · in-browser

Simple Interest Calculator

Calculate simple interest and the final amount for a principal, rate and time.

Private · in-browser

SIP / Investment Calculator

Project the future value of regular monthly investments at an expected annual return.

Private · in-browser

Retirement Calculator

Estimate your retirement savings by combining a starting balance with monthly contributions and growth.

Private · in-browser

Take-Home Pay Calculator

Estimate take-home pay after income tax from a gross salary.

Private · in-browser

Income Tax Calculator

Estimate income tax using progressive tax brackets and see your effective and marginal rates.

Private · in-browser

Sales Tax / VAT / GST Calculator

Add or extract sales tax, VAT or GST from any amount at a chosen rate.

Private · in-browser

Mortgage Affordability Calculator

Estimate how much home you can afford from income, debts and a target payment.

Private · in-browser

Refinance Calculator

Compare your current loan with a refinance to see monthly and lifetime savings.

Private · in-browser

Down Payment Calculator

Calculate a down payment amount and the resulting loan from price and percentage.

Private · in-browser

Inflation Calculator

See how inflation changes the future value and purchasing power of money over time.

Private · in-browser

ROI Calculator

Calculate return on investment (ROI) and net profit from cost and final value.

Private · in-browser

Break-Even Calculator

Find the number of units you must sell to cover fixed and variable costs.

Private · in-browser

Savings Goal Calculator

Work out the monthly amount to save to hit a target by a deadline, with interest.

Private · in-browser

Loan Comparison Calculator

Compare two loans side by side on monthly payment and total interest.

Private · in-browser

Amortization Schedule Calculator

Generate a full amortization schedule showing principal, interest and balance each month.

Private · in-browser

Tip Calculator

Calculate the tip and split the bill between any number of people.

Private · in-browser

Discount Calculator

Find the sale price and amount saved from an original price and discount percent.

Private · in-browser

India Calculators

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GST Calculator (India)

Add or remove GST (5%, 12%, 18%, 28%) on any amount, with CGST/SGST split — in your browser.

Private · in-browser

Income Tax Calculator India (Old vs New Regime)

Compare income tax under the old and new regimes for FY 2025-26 with rebate and cess.

Private · in-browser

EMI Calculator (India)

Calculate loan EMI in ₹ with total interest and amortization — home, car or personal loans.

Private · in-browser

SIP Calculator (India)

Project mutual fund SIP returns in ₹ for a monthly investment and expected return.

Private · in-browser

Lumpsum Investment Calculator

Estimate the future value of a one-time lumpsum investment in ₹.

Private · in-browser

FD Calculator (Fixed Deposit)

Calculate fixed deposit maturity and interest with quarterly compounding.

Private · in-browser

RD Calculator (Recurring Deposit)

Calculate recurring deposit maturity from a monthly deposit and rate.

Private · in-browser

PPF Calculator

Project your Public Provident Fund maturity over 15+ years at the current rate.

Private · in-browser

NPS Calculator

Estimate your National Pension System corpus at retirement from monthly contributions.

Private · in-browser

HRA Exemption Calculator

Calculate your House Rent Allowance exemption under Section 10(13A).

Private · in-browser

Gratuity Calculator

Estimate gratuity payable from last drawn salary and years of service.

Private · in-browser

EPF Calculator

Project your Employees’ Provident Fund corpus with salary growth and interest.

Private · in-browser

Capital Gains Tax Calculator (LTCG/STCG)

Estimate short- and long-term capital gains tax on equity and other assets.

Private · in-browser

TDS Calculator

Calculate Tax Deducted at Source on a payment at a given rate.

Private · in-browser

Salary CTC to In-Hand Calculator

Estimate your monthly in-hand salary from annual CTC after PF, tax and professional tax.

Private · in-browser

Home Loan Eligibility Calculator

Estimate the home loan amount you’re eligible for based on income and obligations.

Private · in-browser

Stamp Duty Calculator

Estimate stamp duty and registration charges on a property purchase.

Private · in-browser

Health & Fitness

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BMI Calculator

Calculate your Body Mass Index and see your weight category instantly.

Private · in-browser

BMR & Calorie (TDEE) Calculator

Find your basal metabolic rate and daily calorie needs (TDEE) by activity level.

Private · in-browser

Body Fat Percentage Calculator

Estimate body fat percentage using the US Navy method.

Private · in-browser

Ideal Weight Calculator

Estimate your ideal body weight for your height.

Private · in-browser

Macro Calculator

Split your daily calories into protein, carbs and fat grams.

Private · in-browser

Water Intake Calculator

Estimate how much water to drink daily based on your weight and exercise.

Private · in-browser

Pregnancy Due Date Calculator

Estimate your due date from your last menstrual period (Naegele’s rule).

Private · in-browser

Ovulation & Fertility Calculator

Estimate your ovulation date and fertile window from your cycle.

Private · in-browser

Running Pace Calculator

Calculate your pace per km and speed from distance and time.

Private · in-browser

Calories Burned Calculator

Estimate calories burned for an activity from its MET value, your weight and duration.

Private · in-browser

Guides

All 16 guides →

A calculator gives you a number. These explain where it comes from, which rules apply and how to act on it — with worked examples you can check line by line.

About ZoolTools

ZoolTools is a growing collection of 114+ free online tools and calculators — everything from image and PDF utilities to text and developer tools, unit and currency converters, and finance, tax and health calculators — all in one fast, no-nonsense place.

Privacy is built in. File tools such as image compression, PDF editing and format conversion run entirely in your browser — your files never leave your device and nothing is uploaded to a server. That means instant results, no waiting on uploads, and no privacy trade-offs.

There’s no sign-up, no paywall and no clutter. Open any tool and start using it right away on desktop or mobile. Every calculator uses standard, documented formulas that are validated against shared test cases, so you can trust the numbers.

Frequently asked questions

Yes — every tool on ZoolTools is completely free to use, with no limits, trials or hidden charges.