Schedulers

Discover the various schedulers available for image generation.

What schedulers do

Schedulers are algorithms that control the progression of the denoising process in generative models. When generating an image, the model starts with random noise and progressively refines this noise into a coherent image. The scheduler dictates how the noise reduction happens over each iteration, impacting the quality, speed, and style of the generated image.

Supported schedulers

Although the scheduler parameter is optional (the model's own scheduler is used by default), you can specify a different scheduler from the following table.

Scheduler	Friendly name	Description
`Default`	Depends on model	The default scheduler used by the Stable Diffusion model.
`DDIM`	DDIM	Direct implementation of DDIM sampling method.
`DDIMScheduler`	DDIM	Accelerates denoising with fewer steps, maintaining high quality.
`DDPMScheduler`	DDPM	Standard scheduler following the original diffusion process.
`DEISMultistepScheduler`	DEIS Multistep	Efficient denoising with multiple steps for improved quality.
`DPMSolverSinglestepScheduler`	DPM-Solver Single-step	Single-step solver for direct denoising efficiency.
`DPMSolverMultistepScheduler`	DPM-Solver Multi-step	Multi-step solver enhancing denoising accuracy and stability.
`DPMSolverMultistepInverse`	DPM-Solver Multi-step Inverse	Inverse multi-step solver for reverse processes.
`DPM++`	DPM++	Basic implementation of DPM++ sampling method.
`DPM++ Karras`	DPM++ Karras	DPM++ scheduler with Karras noise scheduling.
`DPM++ 2M`	DPM++ 2M	Enhanced DPM++ with 2nd-order multistep method.
`DPM++ 2M Karras`	DPM++ 2M Karras	Advanced Karras scheduler with second-order method.
`DPM++ 2M SDE Karras`	DPM++ 2M SDE Karras	Combines second-order and SDE techniques for superior denoising.
`DPM++ 2M SDE`	DPM++ 2M SDE	Second-order scheduler with SDE for robust image generation.
`DPM++ 3M`	DPM++ 3M	Advanced DPM++ with 3rd-order multistep method.
`DPM++ 3M Karras`	DPM++ 3M Karras	Third-order DPM++ with Karras noise scheduling.
`DPM++ SDE Karras`	DPM++ SDE Karras	Karras method integrated with SDE for optimal denoising.
`DPM++ SDE`	DPM++ SDE	Stochastic differential equations-based scheduler for high-quality images.
`EDMEulerScheduler`	EDM Euler	Enhanced denoising with modifications to the Euler method.
`EDMDPMSolverMultistepScheduler`	EDM DPM-Solver Multi-step	EDM-enhanced multi-step solver for precision and quality.
`Euler`	Euler	Basic Euler method implementation.
`EulerDiscreteScheduler`	Euler	Utilizes Euler's method for simple and effective denoising.
`Euler Karras`	Euler Karras	Euler method with Karras noise scheduling.
`Euler a`	Euler Ancestral	Euler method with ancestral sampling variant.
`EulerAncestralDiscreteScheduler`	Euler Ancestral	Euler's method with ancestral sampling for better quality.
`FlowMatchEulerDiscreteScheduler`	FlowMatch Euler	Flow matching techniques combined with Euler's method for precision.
`Heun`	Heun	Basic implementation of Heun's method.
`HeunDiscreteScheduler`	Heun	Uses Heun's method for precise and efficient denoising.
`Heun Karras`	Heun Karras	Heun's method with Karras noise scheduling.
`IPNDMScheduler`	IPNDM	Improved pseudo numerical methods for efficient diffusion.
`KDPM2DiscreteScheduler`	KDPM2	Second-order scheduler for refined noise reduction.
`KDPM2AncestralDiscreteScheduler`	KDPM2 Ancestral	Second-order scheduler incorporating ancestral sampling.
`LCM`	LCM	Basic implementation of Low-Complexity Method.
`LCMScheduler`	LCM	Low-complexity scheduler designed for efficient denoising with minimal computational resources.
`LMS`	LMS	Basic Linear Multi-Step method implementation.
`LMSDiscreteScheduler`	LMS	Linear multistep method for balanced speed and quality.
`LMS Karras`	LMS Karras	Linear Multi-Step method with Karras noise scheduling.
`PNDMScheduler`	PNDM	Combines numerical methods with diffusion for effective denoising.
`TCDScheduler`	TCD	Time-continuous diffusion scheduler for smooth denoising processes.
`UniPC`	UniPC	Basic Universal PC scheduler implementation.
`UniPCMultistepScheduler`	UniPC Multistep	Universal multi-step scheduler for diverse applications.
`UniPC Karras`	UniPC Karras	Universal PC scheduler with Karras noise scheduling.
`UniPC 2M`	UniPC 2M	Second-order Universal PC scheduler.
`UniPC 2M Karras`	UniPC 2M Karras	Second-order Universal PC with Karras scheduling.
`UniPC 3M`	UniPC 3M	Third-order Universal PC scheduler.
`UniPC 3M Karras`	UniPC 3M Karras	Third-order Universal PC with Karras scheduling.