Answers first. Tools underneath.
Thirty-one calculators, converters and text utilities. Type what you need in the bar below and get the answer straight away — or pick a tool and work in it properly.
Paste a paragraph and it counts the words. Type a tool name and it finds the tool.
Percentage Calculator
Five modes: percent of, what percent, increase, decrease, and percentage change — each with the working shown.
yrsAge Calculator
Exact age in years, months and days, plus total weeks and the next birthday countdown.
d±Date Calculator
Days between two dates, or add and subtract days, weeks and months — with a working-days option.
EMILoan & EMI Calculator
Monthly instalment, total interest and a full amortisation schedule you can copy out.
−%Discount & Tax Calculator
Final price after a discount, after tax, or both — and it tells you the order the maths was applied in.
tipTip Splitter
Tip amount and the per-person share, with rounding options so nobody is left owing 3 rupees.
LFuel Cost Calculator
Trip cost from distance, mileage and fuel price — works in km/L, L/100km or MPG.
GPAGPA & Grade Calculator
Credit-weighted GPA on a 4.0 or 5.0 scale, plus a straight weighted-marks mode for coursework.
fxScientific Calculator
Trigonometry, logs, powers and roots with a visible expression line and full keyboard support.
12→Number to Words
Writes any number out in English, in either the international or the lakh–crore system.
IVRoman Numeral Converter
Both directions, 1 to 3,999, with the subtractive-notation rules explained where they bite.
?Random Number Generator
Single draws or bulk lists, with or without repeats, using the browser's cryptographic generator.
BMIBMI Calculator
Body mass index in metric or imperial, with the WHO category bands and a note on what BMI misses.
⇄Unit Converter
Length, mass, volume, area, speed and temperature in one workspace, with exact conversion factors listed.
GBData Storage Converter
Bits to terabytes, with a switch between the 1000-based and 1024-based systems that explains the gap.
UTCTime Zone Converter
Convert a moment between cities, with daylight-saving handled by your browser's own time zone database.
0bNumber Base Converter
Binary, octal, decimal and hex side by side, updating live as you type in any one of them.
#Colour Converter
HEX, RGB and HSL together with a live swatch and the contrast ratio against black and white.
#wWord & Character Counter
Live word, character, sentence and paragraph counts, plus reading time and the keyword frequency table.
AaCase Converter
Nine cases including title case that actually leaves small words alone, plus camel, snake and kebab.
≠Remove Duplicate Lines
Keeps the first or the last copy, optionally ignoring case and surrounding spaces, and counts what it removed.
A↓Sort Lines
Alphabetical, numeric, by length or shuffled — with natural sort so file10 lands after file9.
F/RFind & Replace
Plain or regular-expression replace across the whole text, with a match count before you commit.
ΔText Diff
Line-by-line comparison of two versions with additions, deletions and moved lines marked.
␣Whitespace Cleaner
Strips double spaces, trailing spaces, tabs and stray blank lines — each rule switchable on its own.
/Slug Generator
Turns a headline into a clean URL slug, handling accents, ampersands and stop words sensibly.
LoLorem Ipsum Generator
Placeholder text by paragraph, sentence or word count, in classic Latin or plain English filler.
←Reverse Text
Reverse the whole string, the word order, or each word in place — emoji-safe.
<>HTML to Plain Text
Strips tags and decodes entities while keeping paragraph breaks and list structure readable.
M↓Markdown to HTML
Live preview and copyable HTML for the common Markdown syntax — headings, lists, links, code and tables.
))Text to Speech
Reads your text aloud using the voices already installed on your device, with speed and pitch control.
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Why these tools behave differently
Most online utilities send your input to a server, run it there, and send the result back. NechVibes does not. Every tool on this site is plain JavaScript that runs inside your own browser tab, which has three practical consequences worth knowing about.
Your text and numbers never leave the device. There is no upload step, so there is nothing on our side to store, log or leak. You can check this yourself: open your browser's network panel, use any tool, and watch that no request goes out.
The tools keep working offline. Once a page has loaded, you can lose your connection and the tool still runs. Handy on a patchy mobile connection or a plane.
Very large inputs are limited by your device, not by us. There is no file-size cap or daily quota, but a phone will slow down on a 50 MB paste where a laptop will not. Where a tool has a practical limit, its page says so.
The trade-off is honest: a few things genuinely need a server — live currency rates, IP lookups, anything that crawls a website — so we do not pretend to offer them. A tool that looks like it works but quietly returns nothing useful is worse than no tool at all.