How to Build an Object Detection Model Without Code
To build an object detection model with no code, upload images with bounding-box labels, tell TensorTurn's chat which objects to detect, and it trains an Ultralytics YOLO model on an isolated cloud GPU — after running image health checks that catch duplicates, near-duplicates, leakage and likely-mislabeled boxes — then deploys the weights as a /predict API that returns boxes, classes and confidences. Object detection finds where objects are and how many there are, which is what you want when location and counts matter, not just a single whole-image label.
Detection vs. classification: pick the right task
Object detection locates each object with a bounding box and can find many objects in one image; image classification assigns one label to the whole image. Choose detection when you need position or counts — counting items on a shelf, finding every defect on a part, locating people and vehicles in a frame, reading gauges. If you only need 'what is this an image of,' classification is simpler and needs far less labeling. TensorTurn runs the YOLO/Ultralytics family for detection and picks the model size to fit your dataset and GPU.
What data you need
- Images plus bounding-box annotations in YOLO txt, COCO json or VOC xml — the format is auto-detected.
- Roughly 150-300+ tight, accurate boxes per class as a working minimum; small, crowded or fine-grained objects need more.
- A consistent class definition and complete labeling — every instance in an image boxed, because unlabeled objects teach the model to ignore them.
- Images that match production conditions: the same distances, backgrounds, lighting and camera you will run inference on.
- Upload as zip, rar or 7z, or from a URL.
| What you provide | What TensorTurn does | How it's evaluated |
|---|---|---|
| Labeled images (boxes) | auto-detects format, runs the image health check | flags duplicates, leakage and bad labels before training |
| Classes to detect (in chat) | trains Ultralytics YOLO on a T4, L4 or A10G | self-heals failing cells, up to 100 retries |
| A held-out split | computes detection metrics | mAP50, mAP50-95, per-class precision and recall |
| The best weights | deploys a /predict endpoint | returns boxes, classes and confidences per image |
How to build an object detection model with TensorTurn (no code)
- Upload your annotated image dataset (format auto-detected).
- Run the image health check: perceptual-hash duplicates, blur and exposure, and a DINOv2 semantic pass for near-duplicates, train/test leakage and likely-mislabeled images. Fix or drop what it flags.
- In chat: 'Train an object detector for the classes crack, dent and scratch.'
- TensorTurn generates and runs the Ultralytics training notebook on a cloud GPU, self-healing errors automatically.
- Review mAP50, mAP50-95, per-class precision and recall, and sample predictions with boxes drawn on validation images.
- Deploy a /predict endpoint that serves the weights, with an inference playground.
How it's evaluated
Detection quality is reported as mean Average Precision. mAP50 uses a loose overlap threshold (IoU 0.5) and answers 'did we find the object roughly,' while mAP50-95 averages across stricter overlaps and rewards tight, accurate boxes. Read per-class precision and recall too, because a strong overall number can hide one class the model keeps missing. Always eyeball sample predictions — and take leakage seriously, since duplicate or near-duplicate images bleeding across train and test inflate mAP and mask a model that will not generalize.
How accurate can it be?
Accuracy is dominated by label quality and object size, not model choice. Large, clear, well-labeled objects can reach mAP50 of 0.85-0.95; small, occluded or crowded objects realistically land at 0.40-0.70, and too few boxes per class produces an unreliable detector. When results disappoint, the fix is almost always more and better-labeled examples of the hard cases, not a bigger model. For long or heavy runs you can connect your own GPU, or pool several of your own machines into one run, with a one-line, outbound-HTTPS-only command that works behind any firewall.
Deploy as an API
Publish an authenticated /predict endpoint on Modal secured with a SHA-256-hashed Bearer key and per-call logging, scaling to zero when idle. Send an image and receive boxes, classes and confidences; the playground provides cURL, JavaScript, Python and Rust snippets. It also serves ONNX-exported weights if you prefer that runtime.
Frequently asked questions
How is this different from the YOLO custom-dataset guide?
Same engine — Ultralytics YOLO. This page covers object detection in general (choosing detection vs classification, data and evaluation), while the YOLO guide is a focused walkthrough of training on your own dataset.
What annotation formats are supported?
YOLO txt, COCO json and VOC xml, all auto-detected, so you do not have to convert formats by hand before uploading.
How many labeled images do I need?
Roughly 150-300 tight boxes per class as a minimum. Small, varied or crowded objects need considerably more to reach usable accuracy.
How is accuracy measured?
mAP50 and mAP50-95, plus per-class precision and recall. Also inspect sample predictions, not only the aggregate number.
Can I train on my own GPU?
Yes. One outbound-HTTPS-only command connects a machine behind any firewall, and you can pool several of your own machines into one run.
Is the deployed detector fast enough for real time?
The endpoint returns detections per image and scales to zero when idle. Throughput depends on image size and the chosen GPU, so test your exact case in the playground.