Fixer API

Powered by 15+ exchange rate data sources, the Fixer API is capable of delivering real-time exchange rate data for 170 world currencies. The API comes with multiple endpoints, each serving a different use case. Endpoint functionalities include getting the latest exchange rate data for all or a specific set of currencies, converting amounts from one currency to another, retrieving Time-Series data for one or multiple currencies and querying the API for daily fluctuation data.

Throughout this documentation you will learn about API structure, methods, potential errors and code examples. In case there any question is left unanswered, please make sure to contact us and our team will be happy to help out.

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Getting Started

Definitions

Definition Description
API Key A unique key assigned to each API account used to authenticate with the API.
Symbol Refers to the three-letter currency code of a given currency.
Base Currency The currency to which exchange rates are relative to. (If 1 USD = X EUR, USD is the base currency)
Target Currency The currency an amount is converted to. (If 1 USD = X EUR, EUR is the target currency)
Base URL Refers to URL which all API request endpoints and URLs are based on.

API Key

Your API Key is the unique key that is passed into the API base URL's access_key parameter in order to authenticate with the Fixer API.

Base URL:

https://data.fixer.io/api/

Append your API Key: Here is how to authenticate with the Fixer API: 

https://data.fixer.io/api/latest
    ? access_key = API_KEY

API Response

Exchange rates delivered by the Fixer API are by default relative to EUR. All data is returned in standard JSON format and can be parsed easily using any programming language.

Example Response: Below you will find an example API response carrying a number of common world currencies, all relative to the currency EUR and time stamped at the exact time they were collected. 

{
    "success": true,
    "timestamp": 1519296206,
    "base": "EUR",
    "date": "2023-06-03",
    "rates": {
        "AUD": 1.566015,
        "CAD": 1.560132,
        "CHF": 1.154727,
        "CNY": 7.827874,
        "GBP": 0.882047,
        "JPY": 132.360679,
        "USD": 1.23396,
    [...]
    }
}

As illustrated above, the API's response - when queried for real-time exchange rates - always contains a timestamp object containing a standard UNIX time stamp indicating the time the given exchange rate data was collected, a base object containing the three-letter currency code of the base currency, a date object containing the date the given exchange rate data was collected, and a rates object containing the actual exchange rate data.

Further below, in the Endpoints section, the API response structure will be discussed in detail.

Available Endpoints

The Fixer API comes with X API endpoints, each providing a different functionality. Please note that depending on your subscription plan, certain API endpoints may or may not be available.

  • Latest rates endpointReturns real-time exchange rate data for all available or a specific set of currencies.
  • Convert endpointAllows for conversion of any amount from one currency to another.
  • Historical rates endpointReturns historical exchange rate data for all available or a specific set of currencies.
  • Time-Series data endpointReturns daily historical exchange rate data between two specified dates for all available or a specific set of currencies.
  • Fluctuation data endpointReturns fluctuation data between two specified dates for all available or a specific set of currencies.

SSL Connection

All paid subscription plans available on Fixer.io come with 256-bit SSL encryption. To connect to the API via SSL, simply use the https protocol instead of standard http.

JSONP Callbacks

The Fixer API comes with support for JSONP Callbacks. This feature enables you to specify a function name, pass it into the API's callback GET parameter and cause the API to return your requested API response wrapped inside that function.

Example Call: 

https://data.fixer.io/api/latest
    ? access_key = API_KEY
    & callback = MY_FUNCTION

In the example call above we are requesting the API to use the callback name MY_FUNCTION.

Example Response: Your API response will be wrapped inside your preferred callback function.

({
    "success": true,
    "timestamp": 1519296206,
    "base": "EUR",
    "date": "2023-06-03",
    "rates": {
        "AUD": 1.566015,
        "CAD": 1.560132,
        "CHF": 1.154727,
        "CNY": 7.827874,
        "GBP": 0.882047,
        "JPY": 132.360679,
        "USD": 1.23396,
    [...]
    }
})

Access-Control / CORS

Fixer also supports Cross-Origin Resource Sharing (CORS) and Access-Control Headers. This will enable you to use the Fixer API via Cross-Origin HTTP Requests.

Learn more about CORS »

HTTP ETags

HTTP ETags are a way of reducing the load on your back-end by requesting new Fixer data only if rates have changed since the last API response.

What are ETags?

An ETag is a part of the HTTP protocol and one of the several mechanisms used for cache validation. The ETag is an identifier assigned to a data resource in a server, and if that resource is ever updated at the server, the ETag is changed.

Whenever a resource is requested (via its URL), the data and ETag are retrieved and stored in the Web cache, and the ETag is sent along with subsequent requests. If the ETag at the server has not changed, a "Not Modified" message is returned, and the cached data is used. (Definition by pcmag.com)

ETags - Quickstart Guide

Step 1

Your initial request to the Fixer API will create an ETag object containing a unique ETag key and a Date object containing the exact date and time at which the data was last modified. This data must be cached along with the entire API response in order for ETags to work.

ETag: "202567a75aef2e66a3ebf2366bff048f"
Date: Mon, 12 Apr 2018 11:30:01 GMT
Step 2

Once you make another API request, make sure to include the If-None-Match HTTP header abd set ut to your previously generated ETag value. Moreover, you will need to add the If-Modified-Since HTTP header to your API request containing the date and time data from your last request. 

If-None-Match: "1872ade88f3013edeb33decd74a4f947"
If-Modified-Since: Fri, 10 Apr 2015 12:10:04 GMT
Step 3

Depending on whether or not your result set has updated since your last API request, the API will return either:

  • the results from your initial API request along with a 304 – Not Modified HTTP header indicating that no change has occured. In this case, the size of the API response will be as small as 0.2kb;
  • or new results with an entirely new set of ETag and Date objects indicating that new data has been accessed. In this case, the size of your API response will be normal.

Potential Errors

Whenever a requested resource is not available or an API call fails for another reason, a JSON error is returned. Errors always come with an error code and a description.

Example Error: The following error is returned if your monthly API request volume has been exceeded.

{
  "success": false,
  "error": {
    "code": 104,
    "info": "Your monthly API request volume has been reached. Please upgrade your plan."
  }
}

Other Errors:

Error Code Description
404 The requested resource does not exist.
101 No API Key was specified or an invalid API Key was specified.
103 The requested API endpoint does not exist.
104 The maximum allowed API amount of monthly API requests has been reached.
105 The current subscription plan does not support this API endpoint.
106 The current request did not return any results.
102 The account this API request is coming from is inactive.
201 An invalid base currency has been entered.
202 One or more invalid symbols have been specified.
301 No date has been specified. [historical]
302 An invalid date has been specified. [historical, convert]
403 No or an invalid amount has been specified. [convert]
501 No or an invalid timeframe has been specified. [timeseries]
502 No or an invalid "start_date" has been specified. [timeseries, fluctuation]
503 No or an invalid "end_date" has been specified. [timeseries, fluctuation]
504 An invalid timeframe has been specified. [timeseries, fluctuation]
505 The specified timeframe is too long, exceeding 365 days. [timeseries, fluctuation]

Endpoints

Supported Symbols Endpoint

The Fixer API comes with a constantly updated endpoint returning all available currencies. To access this list, make a request to the API's symbols endpoint.

API Request:

https://data.fixer.io/api/symbols
    ? access_key = API_KEY

Request Parameters:

Parameter Description
access_key [Required] Your API Key.

API Response: 

{
  "success": true,
  "symbols": {
    "AED": "United Arab Emirates Dirham",
    "AFN": "Afghan Afghani",
    "ALL": "Albanian Lek",
    "AMD": "Armenian Dram",
    [...]
    }
}

Response Objects:

Response Object Description
success Returns true or false depending on whether or not your API request has succeeded.
symbols Returns all supported currencies with their respective three-letter currency codes and names.

Latest Rates Endpoint

Depending on your subscription plan, the API's latest endpoint will return real-time exchange rate data updated every 60 minutes, every 10 minutes or every 60 seconds.

API Request:

https://data.fixer.io/api/latest
    ? access_key = API_KEY
    & base = USD
    & symbols = GBP,JPY,EUR

Request Parameters:

Parameter Description
access_key [required] Your API Key.
base [optional] Enter the three-letter currency code of your preferred base currency.
symbols [optional] Enter a list of comma-separated currency codes to limit output currencies.

API Response:

{
    "success": true,
    "timestamp": 1519296206,
    "base": "USD",
    "date": "2023-06-03",
    "rates": {
        "GBP": 0.72007,
        "JPY": 107.346001,
        "EUR": 0.813399,
    }
}

Response Objects:

Response Object Description
success Returns true or false depending on whether or not your API request has succeeded.
timestamp Returns the exact date and time (UNIX time stamp) the given rates were collected.
base Returns the three-letter currency code of the base currency used for this request.
rates Returns exchange rate data for the currencies you have requested.

Historical Rates Endpoint

Historical rates are available for most currencies all the way back to the year of 1999. You can query the Fixer API for historical rates by appending a date (format YYYY-MM-DD) to the base URL.

API Request:

https://data.fixer.io/api/2013-12-24
    ? access_key = API_KEY
    & base = GBP
    & symbols = USD,CAD,EUR

Request Parameters:

Parameter Description
YYYY-MM-DD [required] A date in the past for which historical rates are requested.
access_key [required] Your API Key.
base [optional] Enter the three-letter currency code of your preferred base currency.
symbols [optional] Enter a list of comma-separated currency codes to limit output currencies.

API Response:

{
    "success": true,
    "historical": true,
    "date": "2013-12-24",
    "timestamp": 1387929599,
    "base": "GBP",
    "rates": {
        "USD": 1.636492,
        "EUR": 1.196476,
        "CAD": 1.739516
    }
}

Response Objects:

Response Object Description
success Returns true or false depending on whether or not your API request has succeeded.
historical Returns true if a request for historical exchange rates was made.
date Returns the date for which historical rates were requested.
timestamp Returns the exact date and time (UNIX time stamp) the given rates were collected.
base Returns the three-letter currency code of the base currency used for this request.
rates Returns exchange rate data for the currencies you have requested.

Specify Symbols

To reduce bandwidth you can limit the number of output currencies to a specific set of your choice on most API endpoints. To do so, simply append the Fixer API's symbols parameter to your API request and set it to one or more comma-separated currency codes.

Example:

https://data.fixer.io/api/latest
    ? access_key = API_KEY
    & symbols = USD,CAD,JPY

The API's response for the request above will be limited to the currencies USD, CAD and JPY.

Changing base currency

Provided changing base currency is supported on your subscription plan, you can change the currency to which your output currency rates are relative to by appending the base parameter to your API request URL and setting it to the three-letter code of your preferred base currency.

Example:

https://data.fixer.io/api/latest
    ? access_key = API_KEY
    & base = USD

Please note: The default base currency is EUR.

Convert Endpoint

The Fixer API comes with a separate currency conversion endpoint, which can be used to convert any amount from one currency to another. In order to convert currencies, please use the API's convert endpoint, append the from and to parameters and set them to your preferred base and target currency codes.

It is also possible to convert currencies using historical exchange rate data. To do this, please also use the API's date parameter and set it to your preferred date. (format YYYY-MM-DD)

API Request:

https://data.fixer.io/api/convert
    ? access_key = API_KEY
    & from = GBP
    & to = JPY
    & amount = 25

Request Parameters:

Parameter Description
access_key [required] Your API Key.
from [required] The three-letter currency code of the currency you would like to convert from.
to [required] The three-letter currency code of the currency you would like to convert to.
amount [required] The amount to be converted.
date [optional] Specify a date (format YYYY-MM-DD) to use historical rates for this conversion.

API Response:

{
    "success": true,
    "query": {
        "from": "GBP",
        "to": "JPY",
        "amount": 25
    },
    "info": {
        "timestamp": 1519328414,
        "rate": 148.972231
    },
    "historical": ""
    "date": "2018-02-22"
    "result": 3724.305775
}

Response Objects:

Response Object Description
success Returns true or false depending on whether or not your API request has succeeded.
query > from Returns the three-letter currency code of the currency converted from.
query > to Returns the three-letter currency code of the currency converted to.
query > to Returns the amount that is converted.
info > timestamp Returns the exact date and time (UNIX time stamp) the given exchange rare was collected.
info > rate Returns the exchange rate used for your conversion.
historical Returns true if historical rates are used for this conversion.
date Returns the date (format YYYY-MM-DD) the given exchange rate data was collected.
result Returns your conversion result.

Time-Series Endpoint

If supported by your subscription plan, the Fixer API's timeseries endpoint lets you query the API for daily historical rates between two dates of your choice, with a maximum time frame of 365 days.

API Request:

https://data.fixer.io/api/timeseries
    ? access_key = API_KEY
    & start_date = 2012-05-01
    & end_date = 2012-05-25

Request Parameters:

Parameter Description
access_key [required] Your API Key.
start_date [required] The start date of your preferred timeframe.
end_date [required] The end date of your preferred timeframe.
base [optional] Enter the three-letter currency code of your preferred base currency.
symbols [optional] Enter a list of comma-separated currency codes to limit output currencies.

API Response:

{
    "success": true,
    "timeseries": true,
    "start_date": "2012-05-01",
    "end_date": "2012-05-03",
    "base": "EUR",
    "rates": {
        "2012-05-01":{
          "USD": 1.322891,
          "AUD": 1.278047,
          "CAD": 1.302303
        },
        "2012-05-02": {
          "USD": 1.315066,
          "AUD": 1.274202,
          "CAD": 1.299083
        },
        "2012-05-03": {
          "USD": 1.314491,
          "AUD": 1.280135,
          "CAD": 1.296868
        },
        [...]
    }
}

Response Objects:

Response Object Description
success Returns true or false depending on whether or not your API request has succeeded.
timeseries Returns true if a request to the timeseries endpoint is made.
start_date The start date of your time frame.
end_date The end date of your time frame.
base Returns the three-letter currency code of the base currency used for this request.
rates Returns exchange rate data for the currencies you have requested.

Fluctuation Endpoint

Using the Fixer API's fluctuation endpoint you will be able to retrieve information about how currencies fluctuate on a day-to-day basis. To use this feature, simply append a start_date and end_date and choose which currencies (symbols) you would like to query the API for. Please note that the maximum allowed timeframe is 365 days.

API Request:

https://data.fixer.io/api/fluctuation
    ? access_key = API_KEY
    & start_date = 2015-12-01
    & end_date = 2015-12-24

Request Parameters:

Parameter Description
access_key [required] Your API Key.
start_date [required] The start date of your preferred fluctuation timeframe.
end_date [required] The end date of your preferred fluctuation timeframe.
base [optional] Enter the three-letter currency code of your preferred base currency.
symbols [optional] Enter a list of comma-separated currency codes to limit output currencies.

API Response:

{
    "success":true,
    "fluctuation":true,
    "start_date":"2018-02-25",
    "end_date":"2018-02-26",
    "base":"EUR",
    "rates":{
        "USD":{
            "start_rate":1.228952,
            "end_rate":1.232735,
            "change":0.0038,
            "change_pct":0.3078
        },
        "JPY":{
            "start_rate":131.587611,
            "end_rate":131.651142,
            "change":0.0635,
            "change_pct":0.0483
        },
        [...]
    }
}

Response Objects:

Response Object Description
success Returns true or false depending on whether or not your API request has succeeded.
fluctuation Returns true if a request to the fluctuation endpoint is made.
start_date The start date of your time frame.
end_date The end date of your time frame.
base Returns the three-letter currency code of the base currency used for this request.
rates Returns exchange rate data for the currencies you have requested.
rates > start_rate Returns the exchange collected on your start date.
rates > end_rate Returns the exchange collected on your end date.
rates > change Returns the change (decimal number) of the given currency rate between your start and end date.
rates > change Returns the percentage change of the given currency rate between your start and end date.

Sample Code

PHP (cURL)

Real-time rates: Find below a simple PHP example for getting exchange rate data via the Fixer API's latest endpoint.

// set API Endpoint and API key
$endpoint = 'latest';
$access_key = 'API_KEY';

// Initialize CURL:
$ch = curl_init('https://data.fixer.io/api/'.$endpoint.'?access_key='.$access_key.'');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

// Store the data:
$json = curl_exec($ch);
curl_close($ch);

// Decode JSON response:
$exchangeRates = json_decode($json, true);

// Access the exchange rate values, e.g. GBP:
echo $exchangeRates['rates']['GBP'];

Convert currencies: Here is how to convert currencies using PHP cURL.

// set API Endpoint, access key, required parameters
$endpoint = 'convert';
$access_key = 'API_KEY';

$from = 'USD';
$to = 'EUR';
$amount = 10;

// initialize CURL:
$ch = curl_init('https://data.fixer.io/api/'.$endpoint.'?access_key='.$access_key.'&from='.$from.'&to='.$to.'&amount='.$amount.'');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

// get the JSON data:
$json = curl_exec($ch);
curl_close($ch);

// Decode JSON response:
$conversionResult = json_decode($json, true);

// access the conversion result
echo $conversionResult['result'];

JavaScript (jQuery.ajax)

Real-time rates: Find below a simple jQuery.ajax example for getting exchange rate data via the Fixer API's latest endpoint.

// set endpoint and your access key
endpoint = 'latest'
access_key = 'API_KEY';

// get the most recent exchange rates via the "latest" endpoint:
$.ajax({
    url: 'https://data.fixer.io/api/' + endpoint + '?access_key=' + access_key,
    dataType: 'jsonp',
    success: function(json) {

        // exchange rata data is stored in json.rates
        alert(json.rates.GBP);

        // base currency is stored in json.base
        alert(json.base);

        // timestamp can be accessed in json.timestamp
        alert(json.timestamp);

    }
});

Convert currencies: Here is how to convert currencies using jQuery.ajax.

// set endpoint and your API key
endpoint = 'convert';
access_key = 'API_KEY';

// define from currency, to currency, and amount
from = 'EUR';
to = 'GBP';
amount = '10';

// execute the conversion using the "convert" endpoint:
$.ajax({
    url: 'https://data.fixer.io/api/' + endpoint + '?access_key=' + access_key +'&from=' + from + '&to=' + to + '&amount=' + amount,
    dataType: 'jsonp',
    success: function(json) {

        // access the conversion result in json.result
        alert(json.result);

    }
});

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