Character counter

Estimate an SMS before sending: number of segments, detected encoding, unit price and total cost, based on your account's rate.

URL

POST https://api.smspartner.fr/v1/sms/estimate

Rate limit: 30 requests / 30 seconds

Parameters

Name	Value
apiKey	Your API key
text	Required. Content of the message to estimate. 10,000 characters maximum.
country	Optional. ISO 3166-1 alpha-2 country code (e.g. FR, BE) used to determine the rate. Default value: FR.

A message cannot exceed 10 SMS (segments). Beyond that, the API returns an error.

Example request

{
    "apiKey": "xxx",
    "text": "Thanks for your order, delivery expected tomorrow before noon!",
    "country": "FR"
}

Response

Field	Value
sms_count	Number of SMS segments needed to send the message.
encoding	Detected encoding: GSM-7 (standard alphabet) or UCS-2 (Unicode characters, e.g. emojis, extended accents).
cost_per_sms	Unit price per SMS segment, based on your account's rate.
total_cost	Estimated total cost (cost_per_sms × sms_count).
is_unicode_required	Present and set to true only when the encoding is UCS-2 (the message contains Unicode characters). Absent otherwise.

Response (UCS-2)

{
    "sms_count": 2,
    "encoding": "UCS-2",
    "cost_per_sms": 0.038,
    "total_cost": 0.076,
    "is_unicode_required": true
}

Response (GSM-7)

{
    "sms_count": 1,
    "encoding": "GSM-7",
    "cost_per_sms": 0.038,
    "total_cost": 0.038
}

Errors

On error, the response has the form { "success": false, "message": "..." } with the corresponding HTTP status.

HTTP status	Case
400	Invalid JSON, missing text parameter, text longer than 10,000 characters, or message exceeding 10 SMS.
401	apiKey missing or invalid.
429	Rate limit exceeded (30 requests / 30 seconds).