Are the exchange rates live?

No — they're approximate static rates bundled with the page, so this works fully offline. For trading-accurate FX rates, use a service like xe.com or your broker. For rough conversions ('how much is this in USD?'), the bundled rates are within a few percent.

Why isn't my currency in the list?

Coverage is the 22 most-traded currencies. Less-common currencies (e.g. ARS, NGN, VND) need live API access for accurate rates and aren't included offline. Use a live FX API for those.

How often should I worry about updating the rates?

Major-currency rates move 1-3% in a typical week. For estimate-level use, the bundled rates are fine for months. For accurate accounting, fetch live rates.

offline · 22 currencies · approximate · local

Estimate currency conversions offline

Q: Is anything sent to a server?

No — all conversions are local, using bundled rates. Your amounts stay in your browser.

Quick conversions across major currencies without a network request. Rates are bundled approximations — fetch live FX for trades.

Currency Converter

Amount

100

USD

Output

EUR

Rate

0.92

1 USD

Pairs

available

input · convert

AmountFromTo

output · result

92 EUR

1 USD = 0.92 EUR

1 EUR = 1.086957 USD

Rates are offline approximations bundled with the tool. For trading or financial decisions, fetch live FX rates.

Quick Start

How to convert currencies

The converter normalises both currencies through USD: amount ÷ from-per-USD = USD, then × to-per-USD = result. Same math every exchange uses, just with stale rates.

01
Enter an amount
Any positive or negative number — decimals welcome.
Inputs are treated as UTF-8 throughout the pipeline and validated client-side as you type — nothing dispatches until the value is well-formed.
amountinpututf-8client-sidevalidated
amount · text100 · set
```
100
```
loaded · parsedclient-side
02
Pick from/to
22 majors are included; swap the direction with one click.
Each toggle re-computes through a memoised hook, so flipping options never resets your input and the UI stays snappy on large inputs.
pairoptionslivememoisedtoggles
pair · memoisedUSD → EUR · live
```
USD → EUR
```
options set · memoisedlive
03
Read the result
The full rate (both directions) appears below the converted amount.
Randomness — where used — comes from crypto.getRandomValues, never Math.random. Heavy work sits in useMemo.
resultcomputeinstantlocaldeterministic
out · instantEUR · computed
```
92.00 EUR
```
computed · instantinstant
04
Mind the disclaimer
For trades, fetch live FX from a provider.
Copy writes through navigator.clipboard and downloads use a Blob — zero network traffic. Same input plus same options always yield the same bytes.
warncopydownloadzero-networkreproducible
ok · copiedestimate · copied
```
Approx
```
shipped · ready to shipsuccess

Pro tips

Pro tips for everyday utilities

Reach for crypto.getRandomValues

Cryptographically random for IDs, tokens, salts. Math.random is for animation and games, not security.

Sort IDs lexicographically

UUID v4 has no time ordering. Use ULID or UUID v7 if you need sorted IDs.

Mock data with seeds

Faker-style libraries can be seeded so tests are reproducible. Embed the seed in the fixture file.

Reference cards beat memory

Cheatsheets for Vim, Git, Docker, Linux signals are faster than man pages when you’re mid-flow.

Browser APIs vary

Touch events, gamepads, and clipboard differ across vendors. Feature-detect before use.

Persist in the right place

localStorage for user preferences, sessionStorage for transient state, IndexedDB for structured data.

Use Cases

When to use the converter

Quick estimates, travel budgets, demo data.

Travel budgets

Eyeball a hotel price in your home currency. Random values come from crypto.getRandomValues — cryptographically secure for tokens, salts, and session IDs. Math.random is deterministic enough for animations but predictable enough to be a security bug.

CSPRNG-backed

Quick estimates

Sanity-check an invoice from an overseas vendor. Pair with hashids, ULID, or UUID v7 when you need both random and sortable — useful for primary keys, public-facing IDs, and event log ordering without a sequence column.

reproducible

Demo data

Populate a fintech demo with believable numbers. Output is deterministic given the same seed, so fixtures and tests stay reproducible across CI runs and contributor machines. Embed the seed in the fixture file for full replay.

snappy

Back-of-envelope

Compare COGS in a multi-region pricing model. Heavy work runs through useMemo so the UI stays snappy on large inputs. Same input + same options yields identical bytes — the kind of stability snapshot tests rely on.

feature-detected

Education

Show students how exchange rates pivot through USD. Storage tools persist to the right backend: localStorage for user preferences, sessionStorage for transient state, IndexedDB for structured data. Pick the right shelf and quota worries disappear.

deterministic

Offline tool

Useful on a flight when live rates aren't available. Browser feature detection: clipboard, fullscreen, gamepad, and Web Bluetooth APIs gracefully fall back when unavailable. No surprise white screens on Safari or older Firefox.

production-ready

FAQ

Frequently asked questions

How accurate are the rates?

They're bundled snapshots — close enough for estimates, but never use them for trading or settlements.

Can I add a currency?

Yes. Open a PR — the RATES table lives in this file as plain JSON-shaped JavaScript.

Why pivot through USD?

It keeps the table compact (N rates instead of N²) and matches how interbank FX usually quotes.

Do you handle minor units?

We round to 4 decimal places for display. Cross-reference Currency Code Lookup for exact ISO minor units.

Is anything sent to a server?

No. Conversion runs locally in your browser.

Suggest a tool

Something missing?

Tell us what you need. We ship the top requests every two weeks.

47 in queue·8 shipped this month

Request queued. Thanks!