GPT-SoVITS vs iSpeech

GPT-SoVITS is a free WebUI for few-shot voice conversion and text-to-speech. It can generate speech from a five-second vocal sample, or use one minute of training data to improve voice similarity and realism. Cross-lingual inference supports English, Japanese, Korean, Cantonese, and Chinese. The WebUI includes tools for separating accompaniment, segmenting training sets, multilingual speech recognition, and labeling text. Speech-recognition options include Fun-ASR-Nano, SenseVoice, classic FunASR, and Faster Whisper. The repository also provides an API with GET and POST inference endpoints that return WAV audio streams on success. Installation instructions cover Windows, Linux, and macOS, with Docker Compose services in full and Lite variants. The Lite image omits ASR and UVR5 models; UVR5 models must be downloaded manually, while ASR models download as needed. On macOS, the project temporarily uses CPUs because it reports significantly lower quality from models trained with Mac GPUs. GPT-SoVITS is released under the MIT License and links to Chinese and English user guides.

iSpeech provides text-to-speech and automated speech recognition through APIs, SDKs, and online tools. Its speech API can synthesize audio with multiple voices, formats, bitrates, frequencies, and playback speeds, and supports MathML and SSML. The API can also transcribe submitted audio across multiple languages and recognition models; iSpeech says custom models can be created. The homepage lists support for more than 30 languages. Audio downloads are available in AIFF, MP3, OGG, WMA, FLAC, WAV, A-law, μ-law, VOX, and MP4 formats. Listed access includes Android, iOS, Linux, macOS, web, Windows, API, and extension. The Basic plan is free for personal use, and commercial use is listed as available. Plus costs $2.95 a month, billed monthly, and includes 30-minute recordings, approximately 4,167 words. Premium costs $3.95 a month, billed monthly, with 12-hour recordings, approximately 100,000 words. Pay Per Use costs $50 a month for dynamic TTS usage only and includes 2,000 credits. Pay Per Install costs $0.25 a month and has a 10,000-install minimum.