StartSpeechSynthesisTask - Amazon Polly


Allows the creation of an asynchronous synthesis task, by starting a new SpeechSynthesisTask. This operation requires all the standard information needed for speech synthesis, plus the name of an Amazon S3 bucket for the service to store the output of the synthesis task and two optional parameters (OutputS3KeyPrefix and SnsTopicArn). Once the synthesis task is created, this operation will return a SpeechSynthesisTask object, which will include an identifier of this task as well as the current status. The SpeechSynthesisTask object is available for 72 hours after starting the asynchronous synthesis task.

Request Syntax

POST /v1/synthesisTasks HTTP/1.1 Content-type: application/json { "Engine": "string", "LanguageCode": "string", "LexiconNames": [ "string" ], "OutputFormat": "string", "OutputS3BucketName": "string", "OutputS3KeyPrefix": "string", "SampleRate": "string", "SnsTopicArn": "string", "SpeechMarkTypes": [ "string" ], "Text": "string", "TextType": "string", "VoiceId": "string" }

URI Request Parameters

The request does not use any URI parameters.

Request Body

The request accepts the following data in JSON format.


Specifies the engine (standard or neural) for Amazon Polly to use when processing input text for speech synthesis. Using a voice that is not supported for the engine selected will result in an error.

Type: String

Valid Values: standard | neural

Required: No


Optional language code for the Speech Synthesis request. This is only necessary if using a bilingual voice, such as Aditi, which can be used for either Indian English (en-IN) or Hindi (hi-IN).

If a bilingual voice is used and no language code is specified, Amazon Polly uses the default language of the bilingual voice. The default language for any voice is the one returned by the DescribeVoices operation for the LanguageCode parameter. For example, if no language code is specified, Aditi will use Indian English rather than Hindi.

Type: String

Valid Values: arb | cmn-CN | cy-GB | da-DK | de-DE | en-AU | en-GB | en-GB-WLS | en-IN | en-US | es-ES | es-MX | es-US | fr-CA | fr-FR | is-IS | it-IT | ja-JP | hi-IN | ko-KR | nb-NO | nl-NL | pl-PL | pt-BR | pt-PT | ro-RO | ru-RU | sv-SE | tr-TR | en-NZ | en-ZA

Required: No


List of one or more pronunciation lexicon names you want the service to apply during synthesis. Lexicons are applied only if the language of the lexicon is the same as the language of the voice.

Type: Array of strings

Array Members: Maximum number of 5 items.

Pattern: [0-9A-Za-z]{1,20}

Required: No


The format in which the returned output will be encoded. For audio stream, this will be mp3, ogg_vorbis, or pcm. For speech marks, this will be json.

Type: String

Valid Values: json | mp3 | ogg_vorbis | pcm

Required: Yes


Amazon S3 bucket name to which the output file will be saved.

Type: String

Pattern: ^[a-z0-9][\.\-a-z0-9]{1,61}[a-z0-9]$

Required: Yes


The Amazon S3 key prefix for the output speech file.

Type: String

Pattern: ^[0-9a-zA-Z\/\!\-_\.\*\'\(\):;\$@=+\,\?&]{0,800}$

Required: No


The audio frequency specified in Hz.

The valid values for mp3 and ogg_vorbis are "8000", "16000", "22050", and "24000". The default value for standard voices is "22050". The default value for neural voices is "24000".

Valid values for pcm are "8000" and "16000" The default value is "16000".

Type: String

Required: No


ARN for the SNS topic optionally used for providing status notification for a speech synthesis task.

Type: String

Pattern: ^arn:aws(-(cn|iso(-b)?|us-gov))?:sns:[a-z0-9_-]{1,50}:\d{12}:[a-zA-Z0-9_-]{1,256}$

Required: No


The type of speech marks returned for the input text.

Type: Array of strings

Array Members: Maximum number of 4 items.

Valid Values: sentence | ssml | viseme | word

Required: No


The input text to synthesize. If you specify ssml as the TextType, follow the SSML format for the input text.

Type: String

Required: Yes


Specifies whether the input text is plain text or SSML. The default value is plain text.

Type: String

Valid Values: ssml | text

Required: No


Voice ID to use for the synthesis.

Type: String

Valid Values: Aditi | Amy | Astrid | Bianca | Brian | Camila | Carla | Carmen | Celine | Chantal | Conchita | Cristiano | Dora | Emma | Enrique | Ewa | Filiz | Gabrielle | Geraint | Giorgio | Gwyneth | Hans | Ines | Ivy | Jacek | Jan | Joanna | Joey | Justin | Karl | Kendra | Kevin | Kimberly | Lea | Liv | Lotte | Lucia | Lupe | Mads | Maja | Marlene | Mathieu | Matthew | Maxim | Mia | Miguel | Mizuki | Naja | Nicole | Olivia | Penelope | Raveena | Ricardo | Ruben | Russell | Salli | Seoyeon | Takumi | Tatyana | Vicki | Vitoria | Zeina | Zhiyu | Aria | Ayanda

Required: Yes

Response Syntax

HTTP/1.1 200 Content-type: application/json { "SynthesisTask": { "CreationTime": number, "Engine": "string", "LanguageCode": "string", "LexiconNames": [ "string" ], "OutputFormat": "string", "OutputUri": "string", "RequestCharacters": number, "SampleRate": "string", "SnsTopicArn": "string", "SpeechMarkTypes": [ "string" ], "TaskId": "string", "TaskStatus": "string", "TaskStatusReason": "string", "TextType": "string", "VoiceId": "string" } }

Response Elements

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.


SynthesisTask object that provides information and attributes about a newly submitted speech synthesis task.

Type: SynthesisTask object



This engine is not compatible with the voice that you have designated. Choose a new voice that is compatible with the engine or change the engine and restart the operation.

HTTP Status Code: 400


The provided Amazon S3 bucket name is invalid. Please check your input with S3 bucket naming requirements and try again.

HTTP Status Code: 400


The provided Amazon S3 key prefix is invalid. Please provide a valid S3 object key name.

HTTP Status Code: 400


The specified sample rate is not valid.

HTTP Status Code: 400


The provided SNS topic ARN is invalid. Please provide a valid SNS topic ARN and try again.

HTTP Status Code: 400


The SSML you provided is invalid. Verify the SSML syntax, spelling of tags and values, and then try again.

HTTP Status Code: 400


The language specified is not currently supported by Amazon Polly in this capacity.

HTTP Status Code: 400


Amazon Polly can't find the specified lexicon. This could be caused by a lexicon that is missing, its name is misspelled or specifying a lexicon that is in a different region.

Verify that the lexicon exists, is in the region (see ListLexicons) and that you spelled its name is spelled correctly. Then try again.

HTTP Status Code: 404


Speech marks are not supported for the OutputFormat selected. Speech marks are only available for content in json format.

HTTP Status Code: 400


An unknown condition has caused a service failure.

HTTP Status Code: 500


SSML speech marks are not supported for plain text-type input.

HTTP Status Code: 400


The value of the "Text" parameter is longer than the accepted limits. For the SynthesizeSpeech API, the limit for input text is a maximum of 6000 characters total, of which no more than 3000 can be billed characters. For the StartSpeechSynthesisTask API, the maximum is 200,000 characters, of which no more than 100,000 can be billed characters. SSML tags are not counted as billed characters.

HTTP Status Code: 400

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following: