Fluctuation

On this page, we’ll dive into the fluctuation endpoint you can use to see how exchange rates changed between two dates, in absolute terms and in percent.

Instead of requesting two historical days and computing the difference yourself, one request returns each currency’s rate at the end of both days and the change in between. Typical uses are “biggest movers” lists, price-adjustment triggers and month-over-month reporting.

GET/v3/fluctuation

Fluctuation

Returns, for every requested currency, its rate at the end of date_from and of date_to (UTC) and how much it changed.

Required attributes

Name
date_from
Type
string
Description
First day, format YYYY-MM-DD. Data are available back to 1999-01-01.
Name
date_to
Type
string
Description
Last day, format YYYY-MM-DD, on or after date_from. The newest allowed day is yesterday.

Optional attributes

Name
base_currency
Type
string
Description
The base currency all rates are expressed in. Defaults to USD.
Name
currencies
Type
string
Description
A list of comma separated currency codes you want to get (EUR,GBP,JPY). By default all currencies are returned.
Name
type
Type
string
Description
Limit the result to fiat, metal or crypto.
Name
format
Type
string
Description
json (default) or csv. The CSV has one row per currency: date_from,date_to,base_currency,currency,start_rate,end_rate,change,change_pct.

Response Properties

Name
start_rate
Type
float
Description
The rate at the end of date_from.
Name
end_rate
Type
float
Description
The rate at the end of date_to.
Name
change
Type
float
Description
end_rate - start_rate.
Name
change_pct
Type
float
Description
The change in percent of start_rate, rounded to 4 decimals. Negative when the currency got cheaper against the base currency.

A request costs one request of your quota. If no rates are stored for one of the two days, the endpoint returns a 404.

Request

GET

/v3/fluctuation

curl -G https://api.currencyapi.com/v3/fluctuation \
    -d date_from=2026-01-01 \
    -d date_to=2026-06-30 \
    -d currencies=EUR,GBP,JPY \
    -H "apikey: YOUR-API-KEY"

Response

{
    "meta": {
        "base_currency": "USD",
        "date_from": "2026-01-01",
        "date_to": "2026-06-30"
    },
    "data": {
        "EUR": {
            "code": "EUR",
            "start_rate": 0.9654,
            "end_rate": 0.8771,
            "change": -0.0883,
            "change_pct": -9.1465
        },
        "GBP": {
            "code": "GBP",
            "start_rate": 0.7988,
            "end_rate": 0.7302,
            "change": -0.0686,
            "change_pct": -8.5879
        },
        "JPY": {
            "code": "JPY",
            "start_rate": 157.21,
            "end_rate": 144.12,
            "change": -13.09,
            "change_pct": -8.3264
        }
    }
}