Loans
Calculate and compare loan payments, borrowing costs and repayment options
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All Tools
Search or browse every ToolZen Hub tool, by section and category.
Investment
Explore investment growth, returns and savings scenarios
Tax
Work through tax-related calculations with clear assumptions
Business
Calculate margins, profit and other practical business metrics
Math
Solve percentage and everyday math problems
Coming soon
- Health Coming soon
- Converter Coming soon
Date Difference Calculator
Find how many days are between two calendar dates, with the difference in years, months and days and in weeks and days.
Date Calculator
Add or subtract days, weeks, months and years from a date, and see the resulting date and its weekday.
Countdown Timer
Set a time and count down to zero, with pause and resume, a large display and the time left in the browser tab.
Stopwatch
Measure elapsed time from zero with start, pause, resume and laps, showing each lap time, the total and the fastest and slowest lap.
Time Zone Converter
Convert a date and time from one time zone to others, with daylight-saving gaps and repeated hours explained, and find times that fall inside everyone's preferred hours. It runs in your browser.
Hours & Timesheet Calculator
Add up the hours you worked across several shifts: enter start and end times and unpaid breaks, including overnight shifts, and see each shift and the total in hours and minutes and in decimal hours. It runs in your browser.
JSON Formatter & Validator
Check JSON against the strict standard, see exactly where it breaks, and format or minify it. It runs in your browser.
Unix Timestamp Converter
Convert Unix timestamps in seconds, milliseconds, microseconds or nanoseconds to a date, and a date and time zone back to a timestamp, with daylight-saving gaps and overlaps explained. It runs in your browser.
Text Diff / Compare
Paste two versions of a text and see what was added, removed and changed, line by line with the changed words marked. It runs in your browser.
JWT Decoder
Read the header and payload of a JSON Web Token, see its claims explained and its times as dates. It does not check the signature. It runs in your browser.
Cron Expression Explainer
Paste a five-field cron expression written in cronie crontab syntax to see what each field means, a plain-language summary and the next five matching times in UTC. It checks the syntax, says what it does not support and runs in your browser.
Base64 Encoder & Decoder
Encode text to Base64 or decode Base64 back to text, with UTF-8 support and a clear message for invalid input. It runs in your browser: nothing is uploaded.
Image Compressor & Resizer
Make a JPEG, PNG or WebP smaller in dimensions and file size, or keep it under a size you choose, and see an honest before and after. It runs in your browser: nothing is uploaded.