# MiniMax FastH3 vs LTX-2.5: inputs, controls and API cost > Compare MiniMax FastH3 and LTX-2.5 APIs: inputs, outputs, streaming delivery and ready-second cost. Choose a Windflow model for your product. Source: https://windflow.online/compare/fast-h3-vs-ltx-2-5 · Updated 2026-10-11 · Windflow Labs **MiniMax FastH3 and LTX-2.5 are both realtime video generation options in Windflow's public catalog.** Choose by the inputs and interaction you need, then evaluate quality and responsiveness with your actual application. This page compares the published serving profiles; it does not present a head-to-head performance experiment. ## Quick decision - Evaluate [MiniMax FastH3](https://windflow.online/models/fast-h3) for: Generated video with synchronised dialogue, ambience and music from one prompt. - Evaluate [LTX-2.5](https://windflow.online/models/ltx-2-5) for: Audio-visual scenes where sound is generated with the picture rather than dubbed after. ## Specifications side by side | Published specification | MiniMax FastH3 | LTX-2.5 | |---|---|---| | Architecture | 35B MiniMax H3 text-to-video-and-audio model, DMD2-distilled to four DiT calls with 90% sparse VSA-H3 attention | 22B joint audio+video DiT, two-stage, generated one window at a time | | Resolution | 960 × 544 | 832 × 448 measured; the canvas is configurable in multiples of 64 | | Playout | 24 | 24 | | Chunk | 345 frames per window (14.38 s at 24 fps; published as the 15 s profile) | 241 frames per window (10.04 s) | | Control latency | A whole window. The pipeline materialises the clip before delivery, so time-to-first-frame equals one generation. | A whole window: the pipeline does not yield progressively, so time-to-first-frame equals one window's generation time. The reference still is published while it runs. | | Inputs | A text prompt with visual, dialogue, soundscape, and music direction | A text prompt and an optional reference still | | Outputs | Video on main_video and generated audio downmixed to mono on main_audio, aligned per window | Video on main_video and the audio generated with it on main_audio, aligned per window | | Delivery | WebRTC | WebRTC | | Session protocol | sdk.realtime.v2 | sdk.realtime.v2 | | Price | $0.0069 per ready second | $0.0040 per ready second | | Implementation status | production | production | Implementation status describes runtime maturity. Live GPU readiness is reported separately; Windflow is in private beta and brings capacity up on demand. ## Input and control fit Both models accept text prompts in the published Windflow profile. LTX-2.5 accepts reference or seed images; MiniMax FastH3 does not in its published profile. Both models do not accept uploaded source clips in the published Windflow profile. Both models do not accept live webcam input in the published Windflow profile. Both models do not accept movement and look controls in the published Windflow profile. A shared session API does not make commands interchangeable. Use each model's supported inputs and control timing. In particular, prompt changes may land at a chunk or generation-window boundary; movement input can represent persistent state until replaced. ## What MiniMax FastH3 is designed for MiniMax FastH3 is the 35-billion-parameter MiniMax H3 text-to-video-and-audio model, distilled to four DiT calls and sparse attention with the open-source FastVideo stack from Hao AI Lab. On Windflow it streams video with generated audio window by window from a text prompt that carries visual, dialogue, soundscape and music direction. - Generated video with synchronised dialogue, ambience and music from one prompt. - Continuous AI channels and episodic streams built window by window. - Short-form portrait or landscape clips for social and marketing tests. - Evaluating MiniMax H3 behind a session API before committing to it. ## What LTX-2.5 is designed for LTX-2.5 is Lightricks' 22-billion-parameter joint audio-and-video diffusion model. On Windflow it generates a stream window by window from a text prompt and an optional reference still, delivering video on main_video and the audio generated with it on main_audio, aligned per window. - Audio-visual scenes where sound is generated with the picture rather than dubbed after. - Continuous AI television or channel formats built from successive windows. - Reference-still-anchored characters and settings across windows. - Comparing a joint audio-video model with video-only alternatives on one protocol. ## Compare a realistic session budget - MiniMax FastH3: $0.0069 per ready second, or $4.17 for ten ready minutes. - LTX-2.5: $0.0040 per ready second, or $2.40 for ten ready minutes. Queueing and worker startup are free. A ready owner session can remain billable while delivery is paused or unwatched; release it when done. Independent sessions carry independent meters. Use the [cost calculator](https://windflow.online/tools/ai-video-cost-calculator) to estimate your duration and daily sessions. ## Evaluate before choosing Use one repeatable input sequence, the same client and network, and equivalent output expectations. Record first visible frame, control-to-visible delay, frame gaps, scene continuity and rejected controls. Run several starts and a sustained session. If serving profiles differ, label the differences instead of treating displayed FPS as directly comparable native generation speed. See [the latency measurement guide](https://windflow.online/guides/measure-realtime-video-latency) and [the model selector](https://windflow.online/tools/ai-video-model-selector) for a reproducible decision process. ## Sources - [hao-ai-lab/FastVideo on GitHub](https://github.com/hao-ai-lab/FastVideo) — Apache-2.0 (framework) - [Lightricks/LTX-2 on GitHub](https://github.com/Lightricks/LTX-2) — LTX-2 Community License - [Lightricks/LTX-2.5 on Hugging Face](https://huggingface.co/Lightricks/LTX-2.5) ## FAQ ### Is MiniMax FastH3 better than LTX-2.5? The answer depends on the inputs, control behavior, quality and output your product requires. The published specifications identify capability differences; an application-level evaluation establishes performance for your scenario. ### Can I switch between these models through the same API? Windflow keeps the session lifecycle common. Your application must adapt to each model's supported inputs, commands, output tracks and generation timing. ### Do the published prices guarantee available GPU capacity? No. Rates and implementation status are catalog facts. Live readiness is a separate operational signal, and private-beta access is required to run sessions.