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Text-to-speech (TTS) API Documentation

The Voice RSS Text-To-Speech API creates high quality audio stream. The API doesn’t support callbacks and it synchronously returns audio data or an error message in the same request.

The Text-To-Speech API provides a very easy and simple one-line use. Just put the API key and language in the URL and you'll receive an audio data containing the specified text.


The Text-To-Speech API supports the following protocols:


URL format

The API has the following URL format:

or the following via HTTPS

Where <parameters> is list of parameters that API supports. The parameters may be provided in query string (HTTP GET) or as form parameters (HTTP POST) as well.

Example of request

The following example demonstrats request via HTTP GET:

http://api.voicerss.org/?key=<API key>&hl=en-us&src=Hello, world!

Where <API key> is the API key under the account.


The Text-To-Speech API supports the following list of parameters. The parameters have name-value pair (NVP) format.

Parameter name Parameter description
key The API key (mandatory)
src The textual content for converting to speech (length limited by 100KB) (mandatory).
hl The textual content language. Allows values: see Languages. (mandatory)
r The speech rate (speed). Allows values: from -10 (slowest speed) up to 10 (fastest speed). Default value: 0 (normal speed). (optional)
c The speech audio codec. Allows values: see Audio Codecs. Default value: WAV. (optional)
f The speech audio formats. Allows values: see Audio Formats. Default value: 8khz_8bit_mono. (optional)
ssml The SSML textual content format. Allows values: true and false. Default value: false. (optional)
b64 Defines output as a Base64 string format (for an internet browser playing). Allows values: true and false. Default value: false. (optional)


The API allows convert textual content to audio format in the following languages:

Language code Language name
ca-es Catalan
zh-cn Chinese (China)
zh-hk Chinese (Hong Kong)
zh-tw Chinese (Taiwan)
da-dk Danish
nl-nl Dutch
en-au English (Australia)
en-ca English (Canada)
en-gb English (Great Britain)
en-in English (India)
en-us English (United States)
fi-fi Finnish
fr-ca French (Canada)
fr-fr French (France)
de-de German
it-it Italian
ja-jp Japanese
ko-kr Korean
nb-no Norwegian
pl-pl Polish
pt-br Portuguese (Brazil)
pt-pt Portuguese (Portugal)
ru-ru Russian
es-mx Spanish (Mexico)
es-es Spanish (Spain)
sv-se Swedish (Sweden)

Audio Codecs

The API allows convert textual content to audio format in the following codecs:

Audio codec

Audio Formats

The API allows convert textual content to audio format in the following formats:

Audio format code Audio format description
8khz_8bit_mono 8 kHz, 8 Bit, Mono
8khz_8bit_stereo 8 kHz, 8 Bit, Stereo
8khz_16bit_mono 8 kHz, 16 Bit, Mono
8khz_16bit_stereo 8 kHz, 16 Bit, Stereo
11khz_8bit_mono 11 kHz, 8 Bit, Mono
11khz_8bit_stereo 11 kHz, 8 Bit, Stereo
11khz_16bit_mono 11 kHz, 16 Bit, Mono
11khz_16bit_stereo 11 kHz, 16 Bit, Stereo
12khz_8bit_mono 12 kHz, 8 Bit, Mono
12khz_8bit_stereo 12 kHz, 8 Bit, Stereo
12khz_16bit_mono 12 kHz, 16 Bit, Mono
12khz_16bit_stereo 12 kHz, 16 Bit, Stereo
16khz_8bit_mono 16 kHz, 8 Bit, Mono
16khz_8bit_stereo 16 kHz, 8 Bit, Stereo
16khz_16bit_mono 16 kHz, 16 Bit, Mono
16khz_16bit_stereo 16 kHz, 16 Bit, Stereo
22khz_8bit_mono 22 kHz, 8 Bit, Mono
22khz_8bit_stereo 22 kHz, 8 Bit, Stereo
22khz_16bit_mono 22 kHz, 16 Bit, Mono
22khz_16bit_stereo 22 kHz, 16 Bit, Stereo
24khz_8bit_mono 24 kHz, 8 Bit, Mono
24khz_8bit_stereo 24 kHz, 8 Bit, Stereo
24khz_16bit_mono 24 kHz, 16 Bit, Mono
24khz_16bit_stereo 24 kHz, 16 Bit, Stereo
32khz_8bit_mono 32 kHz, 8 Bit, Mono
32khz_8bit_stereo 32 kHz, 8 Bit, Stereo
32khz_16bit_mono 32 kHz, 16 Bit, Mono
32khz_16bit_stereo 32 kHz, 16 Bit, Stereo
44khz_8bit_mono 44 kHz, 8 Bit, Mono
44khz_8bit_stereo 44 kHz, 8 Bit, Stereo
44khz_16bit_mono 44 kHz, 16 Bit, Mono
44khz_16bit_stereo 44 kHz, 16 Bit, Stereo
48khz_8bit_mono 48 kHz, 8 Bit, Mono
48khz_8bit_stereo 48 kHz, 8 Bit, Stereo
48khz_16bit_mono 48 kHz, 16 Bit, Mono
48khz_16bit_stereo 48 kHz, 16 Bit, Stereo
alaw_8khz_mono ALaw, 8 kHz, Mono
alaw_8khz_stereo ALaw, 8 kHz, Stereo
alaw_11khz_mono ALaw, 11 kHz, Mono
alaw_11khz_stereo ALaw, 11 kHz, Stereo
alaw_22khz_mono ALaw, 22 kHz, Mono
alaw_22khz_stereo ALaw, 22 kHz, Stereo
alaw_44khz_mono ALaw, 44 kHz, Mono
alaw_44khz_stereo ALaw, 44 kHz, Stereo
ulaw_8khz_mono uLaw, 8 kHz, Mono
ulaw_8khz_stereo uLaw, 8 kHz, Stereo
ulaw_11khz_mono uLaw, 11 kHz, Mono
ulaw_11khz_stereo uLaw, 11 kHz, Stereo
ulaw_22khz_mono uLaw, 22 kHz, Mono
ulaw_22khz_stereo uLaw, 22 kHz, Stereo
ulaw_44khz_mono uLaw, 44 kHz, Mono
ulaw_44khz_stereo uLaw, 44 kHz, Stereo


The Text-To-Speech API returns the following errors:

Error description
The account is inactive!
The subscription is expired or requests count limitation is exceeded!
The request content length is too large!
The language does not support!
The language is not specified!
The text is not specified!
The API key is not available!
The API key is not specified!
The subscription does not support SSML!