Model reference · open weights
Sa2VA is an open-weight language model from ByteDance. Sa2VA-8B (FP32) weighs 16.3 GB; the smallest configuration that runs it is 2× RTX 3060 12 GB.
For self-hosting, compare this build's requirements below with the GPU you plan to rent.
Summary of the ByteDance/Sa2VA-8B model card, 2026-10-01
What it is
| Released by | ByteDance |
|---|---|
| Released | 2025-01-07 |
| Parameters | 8.3B |
| VRAM | 16.3 GB for the weights |
What it runs on
| Card | Requests at once | Context max | Memory | |
|---|---|---|---|---|
| 8K each | 32K each | |||
| RTX 3060 12 GB … RTX 4060 Ti 16 GB 2 smaller cards | ||||
| RTX 3090 24 GB | 4 | 1 | all 32K | 23.4 GB |
| RTX 4090 24 GB | 4 | 1 | all 32K | 23.4 GB |
| RTX 5090 32 GB | 11 | 2 | all 32K | 31.0 GB |
| L40S 48 GB | 23 | 5 | all 32K | 44.0 GB |
| A100 80 GB | 55 | 13 | all 32K | 78.2 GB |
| H100 80 GB | 52 | 13 | all 32K | 78.1 GB |
| RTX PRO 6000 Blackwell 96 GB | 66 | 16 | all 32K | 93.8 GB |
| DGX Spark (GB10) 128 GB unified | 79 | 19 | all 32K | 107 GB |
| H200 141 GB | 107 | 26 | all 32K | 138 GB |
| B200 180 GB | 142 | 35 | all 32K | 176 GB |
| 2× RTX 3060 12 GB tensor parallel | 2 | 21K | 11.6 GB a card | |
| 2× RTX 4060 Ti 16 GB tensor parallel | 9 | 2 | all 32K | 15.4 GB a card |
| 2× RTX 4090 24 GB tensor parallel | 24 | 6 | all 32K | 23.4 GB a card |
| 2× RTX 3090 24 GB tensor parallel | 24 | 6 | all 32K | 23.4 GB a card |
| Requests at once | 8K tokens each | 32K tokens each |
|---|---|---|
| 1 | 19.4 GB | 22.6 GB |
| 5 | 23.7 GB | 39.8 GB |
| 8 | 26.9 GB | 52.7 GB |
| 16 | 35.5 GB | 87.0 GB |
| 32 | 52.7 GB | 156 GB |
| 64 | 87.0 GB | 293 GB |
One card, with vLLM's small-card settings.
From the model card
[📂 GitHub] [📜 Sa2VA paper] [🚀 Quick Start]
Sa2VA is an MLLM capable of question answering, visual prompt understanding, and dense object segmentation at both image and video levels. It achieves comparable performance to SOTA MLLMs Qwen2-VL and InternVL2.5 on question-answering benchmarks. Additionally, Sa2VA possesses the visual prompt understanding and dense object segmentation capabilities that SOTA MLLMs Qwen2-VL and InternVL2.5 lack. Sa2VA achieves SOTA performance on both image and video grounding and segmentation benchmarks.
We built the Sa2VA series based on Qwen2-VL and InternVL2/2.5. In the following table, we provide some Sa2VA models built on InternVL2.5. Other Sa2VA models will be open-sourced soon.
| Model Name | Base MLLM | Language Part | HF Link |
|---|---|---|---|
| Sa2VA-1B | InternVL2.5-1B | Qwen2.5-0.5B-Instruct | 🤗 link |
| Sa2VA-4B | InternVL2.5-4B | Qwen2.5-3B-Instruct | 🤗 link |
| Sa2VA-8B | InternVL2.5-8B | internlm2_5-7b-chat | 🤗 link |
| Sa2VA-26B | InternVL2.5-26B | internlm2_5-20b-chat | 🤗 link |
| Model Name | MME | MMBench | RefCOCO | RefCOCO+ | RefCOCOg | MeVIS (val_u) | DAVIS |
|---|---|---|---|---|---|---|---|
| Sa2VA-1B | 1504/434 | 71.9 | 79.6 | 73.6 | 77.7 | 53.4 | 69.5 |
| Sa2VA-4B | 1691/610 | 81.8 | 82.4 | 77.6 | 79.7 | 55.9 | 73.7 |
| Sa2VA-8B | 1690/610 | 84.4 | 82.6 | 78.0 | 80.3 | 58.9 | 75.9 |
| Sa2VA-26B | 1698/653 | 85.8 | 82.9 | 79.3 | 81.2 | 61.8 | 78.6 |
We provide an example code to run Sa2VA using transformers.
import torch
from transformers import AutoTokenizer, AutoModel
from PIL import Image
import numpy as np
import os
# load the model and tokenizer
path = "ByteDance/Sa2VA-8B"
model = AutoModel.from_pretrained(
path,
torch_dtype=torch.bfloat16,
low_cpu_mem_usage=True,
use_flash_attn=True,
trust_remote_code=True).eval().cuda()
tokenizer = AutoTokenizer.from_pretrained(path, trust_remote_code=True, use_fast=False)
# for image chat
image_path = "/PATH/TO/IMAGE"
text_prompts = "Please describe the image."
image = Image.open(image_path).convert('RGB')
input_dict = {
'image': image,
'text': text_prompts,
'past_text': '',
'mask_prompts': None,
'tokenizer': tokenizer,
}
return_dict = model.predict_forward(**input_dict)
answer = return_dict["prediction"] # the text format answer
# for image chat with segmentation output
image_path = "/PATH/TO/IMAGE"
text_prompts = "Could you please give me a brief description of the image? Please respond with interleaved segmentation masks for the corresponding parts of the answer."
image = Image.open(image_path).convert('RGB')
input_dict = {
'image': image,
'text': text_prompts,
'past_text': '',
'mask_prompts': None,
'tokenizer': tokenizer,
}
return_dict = model.predict_forward(**input_dict)
answer = return_dict["prediction"] # the text format answer
masks = return_dict['prediction_masks'] # segmentation masks, list(np.array(1, h, w), ...)
# for chat with visual prompt (mask format) input
mask_prompts = np.load('/PATH/TO/pred_masks.npy') # np.array(n_prompts, h, w)
image_path = "/PATH/TO/IMAGE"
text_prompts = "Can you provide me with a detailed description of the region in the picture marked by region1."
image = Image.open(image_path).convert('RGB')
input_dict = {
'image': image,
'text': text_prompts,
'past_text': '',
'mask_prompts': mask_prompts,
'tokenizer': tokenizer,
}
return_dict = model.predict_forward(**input_dict)
answer = return_dict["prediction"] # the text format answer
# for video chat
video_folder = "/PATH/TO/VIDEO_FOLDER"
images_paths = os.listdir(video_folder)
images_paths = [os.path.join(video_folder, image_path) for image_name in images_paths]
if len(images_paths) > 5: # uniformly sample 5 frames
step = (len(images_paths) - 1) // (5 - 1)
images_paths = [images_paths[0]] + images_paths[1:-1][::step][1:] + [images_paths[-1]]
text_prompts = "Please describe the video."
input_dict = {
'video': images_paths,
'text': text_prompts,
'past_text': '',
'mask_prompts': None,
'tokenizer': tokenizer,
}
return_dict = model.predict_forward(**input_dict)
answer = return_dict["prediction"] # the text format answer
# for video chat with segmentation mask output
video_folder = "/PATH/TO/VIDEO_FOLDER"
images_paths = os.listdir(video_folder)
images_paths = [os.path.join(video_folder, image_path) for image_name in images_paths]
text_prompts = "Please segment the person."
input_dict = {
'video': images_paths,
'text': text_prompts,
'past_text': '',
'mask_prompts': None,
'tokenizer': tokenizer,
}
return_dict = model.predict_forward(**input_dict)
answer = return_dict["Quoted from the model card on Hugging Face. The full card is behind the Hugging Face link above.