Percentage Calculator
A little math. A lot less effort.
A LITTLE LESS BUSYWORK
Your everyday tools.
All in one place.
Resize an image. Run the numbers. Clean up your text.
Useful tools for the little things that get in your way.
Free to useBrowser toolsBrowser-based
Start with the essentials
A good place to begin ↙Explore your toolkit
Age Calculator
Calendar age, elapsed days and your next birthday.
Date Calculator
Add days, subtract days, or compare two dates.
Unit Converter
Convert length, mass, volume and eight more measures.
QR Generator
Static URL, text, Wi-Fi and UPI codes. PNG or SVG.
EMI Calculator
Monthly loan payments with a repayment schedule.
SIP Calculator
Project regular monthly contributions with clear assumptions.
Compound Interest Calculator
See how principal grows with periodic compounding.
Simple Interest Calculator
Calculate interest without compounding.
GST Calculator
Add or extract GST with CGST/SGST or IGST breakdown.
VAT / Sales Tax Calculator
Add or extract a tax rate you specify.
Profit Margin Calculator
Compare profit margin and markup.
Markup Calculator
Set a selling price from cost and markup.
Break-even Calculator
Find how many units cover your fixed costs.
Invoice Generator
Invoices, quotations and receipts with local PDF export.
GST Invoice Generator
Indian GST fields, line taxes and a reviewed PDF preview.
Percentage Calculator
Find percentages, without the mental math.
Word Counter
Words, characters, and bytes at a glance.
Resize Image
Set new dimensions. Keep the right proportions.
JSON Formatter
Turn messy JSON into something readable.
Signature Resizer
Crop your signature. Set dimensions. Check readability.
Resize Image in KB
Meet a file size limit. Verify every byte.
Compress Image
Reduce JPG size with adjustable quality.
Discount Calculator
See what you save and what you pay.
Days Between Dates
Calculate the gap between two dates.
Temperature Converter
Convert Celsius, Fahrenheit, and Kelvin.
Case Converter
Switch between upper and lowercase.
Remove Duplicate Lines
Clean up your lists in one click.
URL Encoder / Decoder
Encode and decode URL components.
Merge PDF
Combine documents into one tidy PDF.
Split PDF
Keep just the pages you need.
Images to PDF
Bring your images together in a document.
No tools found
Try a different search or choose another category.
Keep it simple. Keep it yours.
The current tools process inputs in your browser. No account is needed; files are handled in the browser.
Privacy at RedTools
What RedTools processes in your browser, what is saved on your device, and what page requests the hosting provider receives.
Files and tool inputs
The current tools process uploaded files, invoice fields, QR content, text and calculation inputs in the browser. The application does not send those inputs to a processing server or an AI service. Preview and download URLs are temporary browser Blob URLs. Closing the tab releases the active workspace.
What this device remembers
Favorites, recently used tool IDs and the theme choice use local storage. Invoice drafts are saved on this device only when you select Save draft locally. Other tool inputs are not automatically saved by RedTools. Browser features and downloaded files remain under your control. Avoid saving sensitive drafts on shared devices.
Ordinary website requests
Cloudflare hosts the website and receives requests for pages, scripts, fonts and other assets. Those requests can include an IP address and browser information. Local file processing does not mean there are no network requests. This application includes no analytics, advertising scripts or account system.
Clear saved information
Open Privacy & project info from the dashboard and select Clear preferences, history and saved draft to remove RedTools preferences and its saved invoice draft from this browser. Clearing browser site data also removes those entries. Downloaded files must be managed separately.
Review date
This description reflects the application reviewed on 6 October 2026. It should be updated when hosting, storage or data processing changes.