Sam3 Browser Int8
INT8-quantized ONNX models for running SAM3 (Segment Anything Model 3) entirely in the browser via ONNX Runtime Web.
Model source
- Kind
- Other
- File size
- 34.1–466 MB
- Version
- vRevision 970196b
- Updated
- Sep 27, 2026
- Downloads
- 0
- Tasks
- Image segmentation
- Source
- Hugging Face
Source description
SAM3 Browser INT8 — Quantized ONNX Models
INT8-quantized ONNX models for running SAM3 (Segment Anything Model 3) entirely in the browser via ONNX Runtime Web.
Files
| File | Size | Description |
|---|---|---|
sam3_image_encoder.onnx | 466 MB | ViT backbone — encodes the input image into feature maps |
sam3_language_encoder.onnx | 387 MB | CLIP text encoder — converts text prompts into embeddings |
sam3_decoder.onnx | 35 MB | DETR-style decoder — produces boxes, scores, and pixel masks |
clip_tokenizer.json | 1.5 MB | CLIP BPE tokenizer vocabulary (encoder + merge table + byte encoder) |
| Total | ~889 MB |
Tokenizer
clip_tokenizer.json contains the full CLIP BPE tokenizer data needed to tokenize text prompts for the language encoder. It includes:
encoder: BPE token → integer ID mapping (~49,408 entries)merges: BPE merge rules (~48,894 pairs)byte_encoder: byte-to-unicode mapping for UTF-8 handling
This is extracted from OpenAI's CLIP bpe_simple_vocab_16e6.txt.gz and packaged as JSON for browser use. Load it at runtime (~500 KB gzipped by CDN) and use it to tokenize prompts into int64 token sequences of length 32, padded with [START=49406, ...tokens..., END=49407, 0, 0, ...].
Quantization
Dynamic INT8 quantization via onnxruntime.quantization.quantize_dynamic with QUInt8 weights. Original FP32 models totaled ~3.5 GB.
Quality is preserved: the quantized pipeline scores 0.9495 on a test image (vs 0.9471 for FP32).
Usage
These models are designed for browser inference. Load them with ONNX Runtime Web:
Pipeline
- Tokenizer: text prompt →
clip_tokenizer.json→int64[1, 32](CLIP BPE tokens) - Image encoder: input
image(uint8, shape[3, 1008, 1008]) → 6 output tensors (vision pos encodings + backbone FPN features) - Language encoder: input
tokens(int64, shape[1, 32]) →text_attention_mask,text_memory,text_embeds - Decoder: combines encoder outputs + prompt tensors →
boxes,scores,masks
Decoder inputs
| Input | Type | Shape | Source |
|---|---|---|---|
original_height | int64 | scalar | Original image height |
original_width | int64 | scalar | Original image width |
vision_pos_enc_2 | float32 | from encoder | Image encoder output |
backbone_fpn_0/1/2 | float32 | from encoder | Image encoder outputs |
language_mask | float32 | from lang encoder | = text_attention_mask |
language_features | float32 | from lang encoder | = text_memory |
box_coords | float32 | [1, 1, 4] | Zeros for text-only prompting |
box_labels | int64 | [1, 1] | Ones |
box_masks | bool | [1, 1] | Ones |
Performance
| Environment | Score | Total time |
|---|---|---|
| Python FP32 (CPU) | 0.9471 | 7.6s |
| Python INT8 (CPU) | 0.9495 | 4.5s |
| Browser WASM | 0.9402 | 94.7s |
| Browser WebGPU | ~0.94 (est.) | ~6-18s (est.) |
Source
Original SAM3 ONNX models from vietanhdev/segment-anything-3-onnx-models, quantized for browser deployment.
Live demo
Sources
1 source
Sources
1 sourceVerified Sep 27
Model artifacts
7 artifacts
Model artifacts
7 artifactsSource excerpts
2 excerpts
Source excerpts
2 excerpts--- license: apache-2.0 tags: - sam3 - segment-anything - onnx - int8 - browser - webgpu - computer-vision - segmentation pipeline_tag: image-segmentation --- # SAM3 Browser INT8 — Quantized ONNX Models INT8-quantized ONNX models for running [SAM3 (Segment Anything Model 3)](https://github.com/facebookresearch/sam3) entirely in the browser via [ONNX Runtime Web](https://onnxruntime.ai/docs/tutorials/web/). ## Files | File | Size | Description | |---|---|---| | `sam3_image_encoder.onnx` | 466 MB | ViT backbone — encodes the input image into feature maps | | `sam3_language_encoder.onnx` | 387 MB | CLIP text encoder — converts text prompts into embeddings | | `sam3_decoder.onnx` | 35 MB | DETR-style decoder — produces boxes, scores, and pixel masks | | `clip_tokenizer.json` | 1.5 MB | CLIP BPE tokenizer vocabulary (encoder + merge table + byte encoder) | | **Total** | **~889 MB** | | ## Tokenizer `clip_tokenizer.json` contains the full CLIP BPE tokenizer data needed to tokenize text prompts for the language encoder. It includes: - **`encoder`**: BPE token → integer ID mapping (~49,408 entries) - **`merges`**: BPE merge rules (~48,894 pairs) - **`byte_encoder`**: byte-to-unicode mapping for UTF-8 handling This is extracted from OpenAI's CLIP `bpe_simple_vocab_16e6.txt.gz` and packaged as JSON for browser use. Load it at runtime (~500 KB gzipped by CDN) and use it to tokenize prompts into `int64` token sequences of length 32, padded with `[START=49406, ...tokens..., END=49407, 0, 0, ...]`. ## Quantization Dynamic INT8 quantization via `onnxruntime.quantization.quantize_dynamic` with `QUInt8` weights. Original FP32 models totaled ~3.5 GB. Quality is preserved: the quantized pipeline scores **0.9495** on a test image (vs 0.9471 for FP32). ## Usage These models are designed for browser inference. Load them with ONNX Runtime Web: ### Pipeline 1. **Tokenizer**: text prompt → `clip_tokenizer.json` → `int64[1, 32]` (CLIP BPE tokens) 2. **Image encoder**: input `image` (uint8, shape `[3, 1008, 1008]`) → 6 output tensors (vision pos encodings + backbone FPN features) 3. **Language encoder**: input `tokens` (int64, shape `[1, 32]`) → `text_attention_mask`, `text_memory`, `text_embeds` 4. **Decoder**: combines encoder outputs + prompt tensors → `boxes`, `scores`, `masks` ### Decoder inputs | Input | Type | Shape | Source | |---|---|---|---| | `or...
Source context: 0 downloads · 1 likes · Pipeline image-segmentation · Repo rusen/sam3-browser-int8
