Number to Words API

Convert numbers and money amounts to words in English, Spanish, French, German, Portuguese and Italian. Cheque and invoice wording with currencies, decimals, negatives and letter case.

Authentication & base URL

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Endpoints

GET `/v1/number-to-words`

Number to words

Parameter	In	Description	Example
`number` *	query	Number up to 999,999,999,999,999 (decimals with . or ,)	`1234.56`
`lang`	query	en, es, fr, de, pt or it	`en`
`currency`	query	Optional: USD, EUR, GBP, MXN or BRL for amounts in words	`USD`
`case`	query	lower (default), upper, sentence or title	`sentence`
`british`	query	English only: add 'and' (one hundred and five)	`false`

Example

GET /v1/number-to-words?number=1234.56&lang=en&currency=USD&case=sentence&british=false

{
  "number": "1234.56",
  "lang": "en",
  "currency": "USD",
  "words": "One thousand two hundred thirty-four dollars and fifty-six cents"
}

Convert numbers and money amounts to words in English, Spanish, French, German, Portuguese and Italian. Cheque and invoice wording with currencies, decimals, negatives and letter case.

Examples

1234.56 USD (en) → "One thousand two hundred thirty-four dollars and fifty-six cents"
21 EUR (es) → "veintiún euros"
81 (fr) → "quatre-vingt-un"
123456 (de) → "einhundertdreiundzwanzigtausendvierhundertsechsundfünfzig"

Use cases

Invoices and receipts, bank cheques, legal contracts, accessibility (text to speech), education apps.

Why this API

Correct grammar per language: Spanish apocope (veintiún mil), French vingt/cent rules, German compounds, Portuguese "e" rules, Italian elisions.
Currencies: USD, EUR, GBP, MXN, BRL with singular/plural and cents.

Pricing

Free plan with 500 calls per month, then Pro (25,000 calls for $4.99/month) and Ultra (150,000 calls for $14.99/month). See all plans.