Page4 : Live currency & crypto conversion, scientific calculator, graphing calculator (Desmos API), and unit converter
Currency & Crypto Converter + Scientific & Graphing Calculator + Unit Converter
We built this page after spending too much time switching between five different sites just to convert a currency, check a crypto rate, solve an equation and convert a unit — all for the same task. Slim ABBAR and Hafedh KHAYATI put these four tools together so everything you need for calculations and conversions is in one place, always free and always ready.
What you can do here: Convert between 35+ fiat currencies and 200+ cryptocurrencies with live rates. Solve advanced math with a full scientific calculator. Plot functions and curves with the graphing calculator (Desmos API). Convert 150+ measurement units across 22 categories including length, mass, temperature, energy, electrical units and data storage.
Key advantages: No install, no login, completely free. Works on desktop, tablet and mobile. Currency and crypto data comes live from verified sources (exchangerate-api.com and CoinGecko). If something doesn't work as expected, write to us — we personally read every message.
Last updated: March 2026 · For the best experience, accept cookies so all tools can initialize correctly. For any location-based values on this site, confirm your position when prompted to get the most accurate local results.
Use the section menu below to jump directly to the tool you need.
TOOL 1: Currency & Crypto Converter - Live Exchange Rates
What does this converter do?
Instantly convert between 35+ major fiat currencies (USD, EUR, GBP, TND, JPY, CHF, CAD, AUD, and more) and 200+ leading cryptocurrencies (Bitcoin, Ethereum, Solana, Cardano, XRP, Dogecoin, and hundreds more). Supports fiat-to-fiat, crypto-to-crypto, fiat-to-crypto, and crypto-to-fiat conversions in one unified interface.
Live data sources: Fiat rates come from exchangerate-api.com; crypto prices from CoinGecko API - both updated in real time every time you convert.
Typical uses: Travel planning, e-commerce pricing, crypto portfolio tracking, forex analysis, international business transactions, and investment comparison.
Supported fiat (35+): USD, EUR, GBP, TND, JPY, CHF, CAD, AUD, NZD, SEK, NOK, DKK, CNY, HKD, SGD, INR, BRL, MXN, ZAR, SAR, AED, TRY, PLN, CZK, HUF, RON, KRW, MYR, PHP, THB, VND, IDR, PKR, NGN, KES.
Supported crypto (200+): BTC, ETH, SOL, ADA, XRP, DOGE, TRX, LTC, MATIC, AVAX, UNI, LINK, ATOM, XMR, XLM, and 185+ more verified active coins.
Use the Currency ConverterStep-by-step guide
- Amount: Enter any positive number (decimals supported, e.g. 100, 1.5, 1000.99).
- From: Select the source currency (fiat or crypto).
- To: Select the target currency. Mix any types freely.
- Swap: Reverse the direction instantly with one click.
- Convert: Click the pink button to fetch live rates and calculate.
- Result: View the converted amount, the current rate, timestamp, and data sources.
Pro tip: For important financial decisions, always convert right before the transaction to use the current rate.
TOOL 2: Scientific Calculator — Powered by Desmos API
What can this calculator do?
A professional-grade scientific calculator powered by the official Desmos API — the industry-standard math engine used by millions of students, teachers, and engineers worldwide. Embedded directly via API (not an iframe) for faster loading and full precision.
Supported operations: Basic arithmetic, powers and roots, trigonometry (sin, cos, tan, arcsin, arccos, arctan in degrees and radians), logarithms (log base-10, natural log ln, custom base), absolute value, factorial, parentheses for order of operations, and memory functions.
Who benefits: Students solving math homework or preparing for exams, engineers performing complex calculations, researchers analyzing data, teachers creating demonstrations, and anyone needing reliable scientific computation.
Open Scientific CalculatorHow to use
- Click buttons or type directly on your keyboard for faster input.
- Use parentheses
( )to control order of operations. - Press = or Enter to calculate; use C / AC to clear.
- Trigonometric functions work in both degrees and radians — check the mode selector.
Quick examples: 2^8 = 256 | sin(45) = 0.707 | log(1000) = 3 | (5+3)*2 = 16
TOOL 3: Graphing Calculator — Powered by Desmos API
What can this graphing calculator do?
An interactive graphing calculator powered by the official Desmos API — the most widely used math graphing engine in education worldwide. Plot functions, explore curves, and visualize mathematical relationships instantly in your browser.
Capabilities: Plot explicit functions (y = f(x)), parametric curves, polar equations, inequalities, piecewise functions, conic sections (circles, ellipses, parabolas), regressions, and scatter plots. Add multiple expressions simultaneously and see them layered on the same graph.
Who benefits: Students studying algebra, trigonometry, calculus or statistics; teachers creating visual demonstrations; engineers sketching function behaviors; and anyone who wants to visualize a mathematical expression instantly.
Open Graphing CalculatorHow to use the Graphing Calculator
- Type any expression in the left panel (e.g.
y = sin(x),y = x^2 - 3). - Add more curves: Click the
+button to add extra expressions and layer them. - Zoom & pan: Use scroll wheel or pinch gesture to zoom; drag to pan.
- Trace a curve: Click directly on any plotted curve to see exact coordinates.
- Settings: Use the wrench icon to switch degrees/radians, show/hide grid, axes, etc.
Quick examples: y=sin(x) | y=x^2-4x+3 | r=2+3*cos(theta) (polar) | x^2+y^2=25 (circle) | y=sqrt(x) (racine)
Mobile : appuie dans la zone expressions (haut gauche), le clavier s'ouvre. Syntaxe : sqrt(x) = racine | x^2 = carre | x^n = puissance | cbrt(x) = racine cubique | abs(x) = valeur absolue
TOOL 4: Multi Quick Unit Converter - 150+ Units, 22 Categories
What can this converter handle?
The most comprehensive unit converter on the page, with 150+ units across 22 measurement categories. Convert length from nanometers to light-years, mass from nanograms to tonnes, temperature across Celsius/Fahrenheit/Kelvin/Rankine, data from bits to petabytes, and much more - all with precise conversion formulas calculated in real time.
All 22 categories: Length, Mass/Weight, Volume, Surface Area, Time, Temperature, Speed/Velocity, Acceleration, Force, Pressure, Energy/Work, Power, Voltage, Electric Current, Resistance, Capacitance, Electric Charge, Frequency, Angle, Data Storage, Density, Radioactivity.
Who uses this: Physics and engineering students, scientists, developers calculating storage or bandwidth, technicians working with electrical units, teachers, travelers, and anyone dealing with measurement conversions daily.
Open Unit ConverterStep-by-step guide
- Value: Enter the number to convert.
- Category: Choose one of the 22 measurement types.
- From Unit: Select the unit you're converting from.
- To Unit: Select the target unit.
- Swap: Reverse From/To instantly.
- Convert: Click the green button or press Enter.
Real examples: 5 km to miles | 100F to C | 1 light-year to km | 500 MB to GB | 2 hours to seconds | 1 bar to psi
Frequently Asked Questions
Are the currency and crypto rates updated in real time?
Yes. Every time you click Convert, the tool fetches the latest rate from exchangerate-api.com (fiat) or CoinGecko (crypto) and displays the timestamp and source.
How many cryptocurrencies are supported?
The converter includes 200+ active, liquid cryptocurrencies - from Bitcoin and Ethereum to smaller altcoins with active market trading.
Do I need to install or sign up for anything?
No. All four tools — the currency converter, scientific calculator, graphing calculator, and unit converter — run entirely in your browser. No account, no download, no plugin required.
What measurement categories does the unit converter cover?
22 categories: length, mass, volume, surface area, time, temperature, speed, acceleration, force, pressure, energy, power, voltage, current, resistance, capacitance, charge, frequency, angle, data storage, density, and radioactivity - 150+ units in total.
Is the scientific calculator accurate enough for engineering or exams?
Yes. It is powered by the Desmos API, a professional-grade mathematics engine trusted by millions of educators, students, and engineers worldwide. It supports all standard scientific and trigonometric functions at full floating-point precision.
What can I do with the Graphing Calculator?
The graphing calculator (Desmos API) lets you plot any function (y = f(x)), parametric curves, polar graphs, inequalities, and scatter plots in real time. You can add multiple expressions, zoom freely, and trace curves — all in your browser without any install.
Does the page work on mobile phones?
Yes. All four tools are fully responsive and optimized for smartphones and tablets. The scientific calculator uses the Desmos API with auto-scaling. The graphing calculator on mobile uses Desmos' own responsive interface with touch support — pinch to zoom, drag to pan.
Found a bug, have an idea, or want a new tool?
Slim or Hafedh personally reads every message — your feedback directly shapes what we build next.
© 2026 Toolkit Rapid Free — Built by :
Slim ABBAR & Hafedh KHAYATI
Free browser tools for everyone · Zero install · Zero login
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