Inference#
Ultralytics Platform provides browser-based inference for testing trained models and dedicated endpoints for programmatic access.

Predict Tab#
Every model includes a Predict tab for browser-based inference:
- Navigate to your model
- Click the Predict tab
- Upload an image, use an example, or open your webcam
- Review the task-specific overlay, prediction summary, timing, and raw response

Input Methods#
The predict panel supports multiple input methods:
| Method | Description |
|---|---|
| Image upload | Drag and drop or click to upload an image |
| Example images | Click built-in examples (dataset images or defaults) |
| Webcam capture | Live camera feed with single-frame capture |
graph LR
A[Upload Image]:::start --> D[Auto-Inference]:::proc
B[Example Image]:::start --> D
C[Webcam Capture]:::start --> D
D --> E[Results + Overlays]:::out
classDef start fill:#4CAF50,color:#fff
classDef proc fill:#2196F3,color:#fff
classDef out fill:#9C27B0,color:#fffUpload Image#
Drag and drop or click to upload:
- Supported formats: JPEG, PNG, WebP, AVIF, HEIC, JP2, TIFF, BMP, DNG, MPO
- Max size: 10MB
- Auto-inference: Results appear automatically after upload
The predict panel runs inference automatically when you upload an image, select an example, or capture a webcam frame. No button click is needed.
Example Images#
The predict panel shows example images from your model's linked dataset. If no dataset is linked, default examples are used:
| Image | Content |
|---|---|
bus.jpg | Street scene with vehicles |
zidane.jpg | Sports scene with people |
For OBB models, aerial images of boats and airports are shown instead.
Example images are preloaded when the page loads, so clicking an example triggers near-instant inference with no download wait.
Webcam#
Click the webcam card to start a live camera feed:
- Grant camera permission when prompted
- Click the video preview to capture a frame
- Inference runs automatically on the captured frame
- Click again to restart the webcam
View Results#
Inference results display the output appropriate to the model task: boxes, masks, keypoints, oriented boxes, classification scores, semantic coverage, or a depth map. Object results use the dataset class colors when available. The panel also shows preprocess, inference, postprocess, and network timing.
The results panel shows:
| Field | Description |
|---|---|
| Results summary | Detections, classifications, or semantic class coverage |
| Speed stats | Preprocess, inference, postprocess, and network (ms) |
| JSON response | Raw API response in a code block |
Inference Parameters#
Adjust inference behavior with the three sliders below the image:

| Parameter | Range | Default | Description |
|---|---|---|---|
| Confidence | 0.01 – 1.0, steps of 0.01 | 0.25 | Minimum confidence threshold |
| IoU | 0.0 – 0.95, steps of 0.01 | 0.7 | NMS IoU threshold |
| Image Size | 32 – 1280, steps of 32 | 640 | Input resize dimension |
Changing any parameter automatically re-runs inference on the current image with a 500ms debounce. No need to re-upload.
Confidence Threshold#
Filter predictions by confidence:
- Higher (0.5+): Fewer, more certain predictions
- Lower (0.1-0.25): More predictions, some noise
- Default (0.25): Balanced for most use cases
IoU Threshold#
Control Non-Maximum Suppression:
- Higher (0.7+): Allow more overlapping boxes
- Lower (0.3-0.5): Suppress overlapping detections more aggressively
- Default (0.7): Balanced NMS behavior for most use cases
Deployment Predict#
Each running dedicated endpoint includes a Predict tab directly on its deployment card. This uses the deployment's own inference service rather than the shared predict service, letting you test your deployed endpoint from the browser.
Dedicated Endpoint API#
The API Docs card in the model Predict tab contains example Python, JavaScript, and cURL requests. The examples
use placeholders until you deploy the model. After deployment, the deployment card's Code tab fills in its endpoint
URL and the API key available to your workspace.
Authentication#
Include your API key in requests:
Authorization: Bearer YOUR_API_KEYTo run inference from your own scripts, notebooks, or apps, include an API key. Generate one in Settings > API Keys.
Endpoint#
POST https://YOUR_DEPLOYMENT_URL.run.app/predictRequest#
import requests
url = "https://YOUR_DEPLOYMENT_URL.run.app/predict"
headers = {"Authorization": "Bearer YOUR_API_KEY"}
data = {"conf": 0.25, "iou": 0.7, "imgsz": 640}
with open("image.jpg", "rb") as image_file:
response = requests.post(url, headers=headers, files={"file": image_file}, data=data)
print(response.json())
Request Parameters#
| Parameter | Type | Default | Range | Description |
|---|---|---|---|---|
file | file | - | - | Image or video file (required unless source set) |
conf | float | 0.25 | 0.01 – 1.0 | Minimum confidence threshold |
iou | float | 0.7 | 0.0 – 0.95 | NMS IoU threshold |
imgsz | int | 640 | 32 – 1280 | Input image size in pixels |
normalize | bool | false | - | Return bounding box coordinates as 0 – 1 |
decimals | int | 5 | 0 – 10 | Decimal precision for coordinate values |
source | string | - | - | Image URL or base64 string (alternative to file) |
Response#
{
"images": [
{
"shape": [1080, 1920],
"results": [
{
"class": 0,
"name": "person",
"confidence": 0.92,
"box": { "x1": 100, "y1": 50, "x2": 300, "y2": 400 }
},
{
"class": 2,
"name": "car",
"confidence": 0.87,
"box": { "x1": 400, "y1": 200, "x2": 600, "y2": 350 }
}
],
"speed": {
"preprocess": 1.2,
"inference": 12.5,
"postprocess": 2.3
}
}
],
"metadata": {
"imageCount": 1,
"functionTimeCall": 0.018,
"task": "detect",
"version": {
"ultralytics": "8.x.x",
"torch": "2.6.0",
"torchvision": "0.21.0",
"python": "3.13.0"
}
}
}
Response Fields#
| Field | Type | Description |
|---|---|---|
images | array | List of processed images |
images[].shape | array | Image dimensions [height, width] |
images[].results | array | List of detections |
images[].results[].class | int | Class index (integer ID) |
images[].results[].name | string | Class name |
images[].results[].confidence | float | Detection confidence (0-1) |
images[].results[].box | object | Bounding box coordinates |
images[].speed | object | Processing times in milliseconds |
metadata | object | Request metadata and version info |
Task-Specific Responses#
Response format varies by task:
{
"class": 0,
"name": "person",
"confidence": 0.92,
"box": {"x1": 100, "y1": 50, "x2": 300, "y2": 400}
}Rate Limits#
The shared model API is limited to 20 requests/minute for each API key, signed-in caller, or anonymous IP. When
throttled, the API returns 429 with a Retry-After header. See the full
rate-limit reference for all endpoint categories.
Requests sent directly to a dedicated endpoint do not pass through the Platform API rate limiter. For high-volume local inference, see the Predict mode guide.
Error Handling#
Common error responses:
| Code | Message | Solution |
|---|---|---|
| 400 | Invalid image | Check file format |
| 401 | Unauthorized | Verify API key |
| 404 | Model not found | Check model ID |
| 429 | Rate limited | Wait and retry, or send requests directly to a dedicated endpoint |
| 500 | Server error | Retry request |
| 503 | Service unavailable | Predict service starting up or unreachable; wait briefly and retry |
FAQ#
Both inference methods accept video files:
- Dedicated endpoints accept video files directly. Supported formats (up to 100 MB): ASF, AVI, GIF, M4V, MKV, MOV, MP4, MPEG, MPG, TS, WEBM, WMV. Each frame is processed individually and results are returned per frame. See dedicated endpoints for details.
- Shared inference (
/api/models/{id}/predict) uses the same predict service and accepts the same video formats. The browser Predict tab only selects images, so use the API or a dedicated endpoint for video.
The API returns JSON predictions. To visualize:
- Use predictions to draw boxes locally
- Use Ultralytics
plot()method:
from ultralytics import YOLO model = YOLO("yolo26n.pt") results = model("image.jpg") results[0].save("annotated.jpg")See the Predict mode documentation for the full results API and visualization options.
- Predict tab limit: 10 MB
- Dedicated endpoint API limit: 100 MB
- Auto-resize in the Predict tab: Images are resized to the selected
Image Sizebefore upload
Large images are automatically resized while preserving aspect ratio.
The current API processes one image per request. For batch:
- Send separate requests for each image
- Distribute requests across dedicated endpoints when appropriate
- Use local inference for large batches
Batch Inference with Pythonimport concurrent.futures import requests url = "https://predict-abc123.run.app/predict" headers = {"Authorization": "Bearer YOUR_API_KEY"} images = ["img1.jpg", "img2.jpg", "img3.jpg"] def predict(image_path): with open(image_path, "rb") as f: return requests.post(url, headers=headers, files={"file": f}).json() with concurrent.futures.ThreadPoolExecutor(max_workers=4) as executor: results = list(executor.map(predict, images))