Top Free Speech to Text tools, APIs, and Open Source models

Top Free Speech to Text tools, APIs, and Open Source models

What is Speech to Text API?

Speech recognition technology, also known as Automatic Speech Recognition (ASR) or computer speech recognition, allows users to transcribe audio content into written text. The conversion of speech from a verbal to a written format is accomplished through acoustic and language modeling processes. It's important not to confuse speech recognition technology with voice recognition; while the former translates audio to text, the latter is used to identify an individual user's voice.

This technology is utilized across multiple industries, from transcription services and voice assistants to accessibility features and beyond.

Top Open Source (Free) AI Speech Recognition models on the market

For users seeking a cost-effective engine, opting for an open-source model is the recommended choice. Here is the list of best Automatic Speech Recognition Open Source Models:

1. DeepSpeech

DeepSpeech is an open-source, embedded speech-to-text engine that operates in real-time on a variety of devices, ranging from high-powered GPUs to a Raspberry Pi 4. The DeepSpeech library utilises an end-to-end model architecture pioneered by Baidu.

2. Kaldi

Kaldi is a speech recognition software package highly regarded by researchers for many years. Similar to DeepSpeech, it boasts good initial accuracy and is capable of facilitating model training.

Kaldi has an extensive history of testing and is currently employed by numerous companies in their production environments, bolstering developer confidence in its effectiveness.

‍3. Wav2Letter

Wav2Letter is an Automatic Speech Recognition (ASR) Toolkit developed by Facebook AI Research. It is written in C++ and employs the ArrayFire tensor library. Wav2Letter is a moderately precise open-source library that is user-friendly for minor projects.

‍4. SpeechBrain

SpeechBrain is a transcription toolkit based on PyTorch. The platform provides open-source implementations of popular research projects and tightly integrates with HuggingFace, enabling easy access. In general, the platform is clearly defined and regularly updated, making it an uncomplicated tool for training and fine-tuning.

‍5. Coqui

Coqui is a remarkable toolkit for deep learning in Speech-to-Text transcription. It is developed to be utilized in more than twenty language projects with an array of inference and productionization features.

Furthermore, the platform provides custom trained models and has bindings for numerous programming languages, making it easier for deployment.

‍6. Whisper

Whisper, which was released by OpenAI in September 2022, can be considered as one of the leading open source options. This tool can be used in Python or from the command line and allows for multilingual translation.

Additionally, Whisper boasts five different models, each with its own size and capabilities, for users to choose from based on their specific use case.

‍7. Julius

Probably one of the oldest speech recognition software packages ever, as its development began in 1991 at the University of Kyoto. Julius offers a range of features, such as real-time speech-to-text processing, low memory consumption (less than 64MB for 20,000 words), and the ability to generate N-best/Word-graph outputs. It can also function as a server unit and boasts additional advanced features.

8. OpenSeq2Seq

Developed by NVIDIA for training sequence-to-sequence models, this engine has versatile applications beyond speech recognition. It is a dependable option for this use case. Users have the option to create their own training models or use pre-existing ones. It facilitates parallel processing through the use of multiple GPUs or CPUs.

9. Athena

An end-to-end speech recognition engine implementing ASR is written in Python and licensed under the Apache 2.0 license. It supports unsupervised pre-training and multi-GPU training, on the same or multiple machines. The engine is built on top of TensorFlow and has a large model available for both English and Chinese languages.

Cons of Using Open Source AI models

‍While open source models offer many advantages, they also come with some potential drawbacks and challenges. Here are some cons of using open source models:

  • Not Entirely Cost Free: Open-source models, while providing valuable resources to users, may not always be entirely free of cost. Users often need to bear expenses related to hosting and server usage, especially when dealing with large or resource-intensive data sets.
  • Lack of Support: Open source models may not come with official support channels or dedicated customer support teams. If you encounter issues or need assistance, you might have to rely on community forums or the goodwill of volunteers, which can be less reliable than commercial support.
  • Limited Documentation: Some open source models may have incomplete or poorly maintained documentation. This can make it difficult for developers to understand how to use the model effectively, leading to frustration and wasted time.
  • Security Concerns: Security vulnerabilities can exist in open source models, and it may take longer for these issues to be addressed compared to commercially supported models. Users of open source models may need to actively monitor for security updates and patches.
  • Scalability and Performance: Open source models may not be as optimized for performance and scalability as commercial models. If your application requires high performance or needs to handle a large number of requests, you may need to invest more time in optimization.

Why choose Eden AI?

Given the potential costs and challenges related to open-source models, one cost-effective solution is to use APIs. Eden AI smoothens the incorporation and implementation of AI technologies with its API, connecting to multiple AI engines.

Eden AI presents a broad range of AI APIs on its platform, customized to suit your specific needs and financial limitations. These technologies include data parsing, language identification, sentiment analysis, logo recognition, question answering, data anonymization, speech recognition, and numerous other capabilities.

To get started, we offer free $10 credits for you to explore our APIs. 60720 (1).png

Access ASR providers with one API

Our standardized API enables you to integrate Speech to Text APIs into your system with ease by utilizing various providers on Eden AI. Here is the list (in alphabetical order):

  • Amazon Transcribe
  • AssemblyAI
  • Deepgram
  • Gladia
  • Google
  • IBM
  • Microsoft
  • NeuralSpace
  • OpenAI
  • Rev
  • Speechmatics
  • Symbl
  • Voci

1. Amazon Transcribe- Available on Eden AI

Amazon Transcribe simplifies the process for developers to incorporate speech to text capabilities in their applications. It employs Automatic Speech Recognition (ASR), a deep learning method, to promptly and accurately transform speech into text.

This technology can effectively transcribe customer service calls, automate subtitling, and generate media file metadata, establishing a searchable archive.

2. AssemblyAI- Available on Eden AI


Assembly AI enables accurate transcription of audio and video files through its simple API. The Speech-to-Text technology is bolstered by advanced AI models, with features including batch asynchronous transcription, real-time transcription, speaker diarization, and the ability to accept all audio and video formats.

Notably, Assembly AI maintains top-rated accuracy, an automatic punctuation and casing function, word timings, confidence scores, and paragraph detection.

3. Deepgram- Available on Eden AI

Deepgram offers developers the tools required for effortless implementation of AI speech recognition in applications. We possess the ability to manage nearly all audio file formats and provide lightning-fast processing for premium voice experiences.

Deepgram's Automatic Speech Recognition facilitates optimal voice application creation with superior, faster, and more cost-effective transcription on a large scale.

4. Gladia- Available on Eden AI

Gladia's Audio Intelligence API facilitates the capture, enrichment, and utilization of hidden insights within audio data. It is a highly accurate audio transcription solution for real-world business use cases. The API also includes speaker separation and language alternation detection.

5. Google - Available on Eden AI

Speech-to-Text allows for simple integration of Google's speech recognition technologies into applications for developers. Submit an audio file and receive a textual transcription from Speech-to-Text's API service.

6. IBM- Available on Eden AI

IBM Watson's Speech to Text technology facilitates rapid and precise transcription of speech in various languages for a range of applications, not excluding customer self-help, agent aid, and speech analytics.

The technology offers pre-built advanced machine learning models and optional configurations to adapt to your specific requirements.

7. Microsoft- Available on Eden AI

The Universal language model is the default choice for Microsoft Azure Speech-to-Text service. It was developed by Microsoft and is hosted in the cloud. This model is best suited for conversational and dictation scenarios.

However, for unique environments, it is possible to devise and educate bespoke acoustic, language, and pronunciation models for enhanced performance.

8. NeuralSpace- Available on Eden AI

NeuralSpace's Speech To Text (STT) API serves as a bridge to facilitate audio transcriptions. It utilizes state-of-the-art AI models to offer precise transcriptions of all kinds of speech, whether in conversations or alternative forms.

The API caters to diverse languages worldwide, including those with limited digital representation. You can use the API for various use cases, including captioning videos or meetings, voice bots, and automatic transcription.

9. OpenAI- Available on Eden AI

OpenAI has developed and introduced a neural network named Whisper, which achieves high levels of robustness and accuracy similar to humans. It has been trained on 680,000 hours of multilingual and multitasking supervised data gathered from the internet.

The research demonstrates that the utilization of a broad and varied dataset results in enhanced resilience to accents, ambient sound, and specialized terminology. Furthermore, it allows transcription and translation from multiple languages into English.

10. Rev- Available on Eden AI

Rev's STT engine is the most precise speech-to-text model worldwide. It has been trained on over 50,000 hours of relevant data. Streamline your creation process by implementing a universal model that encompasses all accents, dialects, languages, and audio formats. With a smooth API integration, you can remove redundant stages to achieve the desired outcome.

11. Speechmatics- Available on Eden AI

Speechmatics provides speech recognition technology for mission-critical applications, utilizing its any-context recognition engine. Our technology is used by a wide range of enterprises in contact centers, CRM, consumer electronics, security, media & entertainment, and software. Speechmatics transcribes millions of hours globally in over 30 languages each month.

12. Symbl- Available on Eden AI

The Symbl API utilizes cutting-edge machine learning techniques to transcribe speech in real-time and deliver supplementary context-aware analyses, including speaker identification, sentiment analysis, and topic detection.

13. Voci- Available on Eden AI

Voci provides highly advanced and precise transcription services for a range of purposes. Their API is capable of real-time speech recognition, processing vast audio files, and handling various languages and accents, all thanks to Voci's deep neural networks.

As well as this, Voci's services cover text analytics, speaker diarization, and keyword spotting, with exceptional accuracy and minimal lag time. The API can be incorporated into different types of applications including call centers, transcription services, and voice-enabled devices.

Pricing Structure for Speech to Text API Providers

Eden AI offers a user-friendly platform for evaluating pricing information from diverse API providers and monitoring price changes over time. As a result, keeping up-to-date with the latest pricing is crucial. The pricing chart below outlines the rates for smaller quantities for October 2023, as well as you can get discounts for potentially large volumes.

How Eden AI can help you?

Eden AI is the future of AI usage in companies: our app allows you to call multiple AI APIs.
  • Centralized and fully monitored billing on Eden AI for STT APIs
  • Unified API for all providers: simple and standard to use, quick switch between providers, access to the specific features of each provider
  • Standardized response format: the JSON output format is the same for all suppliers thanks to Eden AI's standardization work. The response elements are also standardized thanks to Eden AI's powerful matching algorithms.
  • The best Artificial Intelligence APIs in the market are available: big cloud providers (Google, AWS, Microsoft, and more specialized engines)
  • Data protection: Eden AI will not store or use any data. Possibility to filter to use only GDPR engines.

You can see Eden AI documentation here.

Next step in your project

The Eden AI team can help you with your Speech to Text integration project. This can be done by :

  • Organizing a product demo and a discussion to better understand your needs. You can book a time slot on this link: Contact
  • By testing the public version of Eden AI for free: however, not all providers are available on this version. Some are only available on the Enterprise version.
  • By benefiting from the support and advice of a team of experts to find the optimal combination of providers according to the specifics of your needs
  • Having the possibility to integrate on a third-party platform: we can quickly develop connectors.

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