Image Annotation API

Best-in-class object recognition to power the next generation of computer vision via API.

Use Cases

Our combination of humans and machine learning is built to solve a wide range of use cases. Our goal is to power innovation, wherever that may be.

Pixel Perfection

We focus on quality so you don't have to. Through world-class tooling and a robust quality assurance process, we provide the highest accuracy in the industry.

We understand the need for quality. The prerequisite for an amazing algorithm is immaculate training data. That's where we come in.

We've built advanced tools that allows our Scalers to produce pixel perfect results in minutes. Each request passes multiple trained Scalers for review to ensure we only deliver the best.

  "response": {
    "annotations": [
        "width": 26,
        "height": 74,
        "left": 169,
        "top": 0,
        "label": "car"
        "width": 88,
        "height": 30,
        "left": 191,
        "top": 103,
        "label": "car"
        "width": 62,
        "height": 55,
        "left": 359,
        "top": 31,
        "label": "car"
        "width": 154,
        "height": 81,
        "left": 371,
        "top": 307,
        "label": "car"
  "task_id": "5795c68afce306120434be64",
  "task": { ... }

Comprehensive Tools

We've built tools for a comprehensive set of image annotation requirements. Our API is built to handle a wide range of labeling requirements.

If you don't see a labeling type you're looking for, please contact us. We have many image labeling types in beta.

Developer First

We relentlessly focus on providing the best experience possible for developers.

We do all the heavy lifting in the background so you can get started with just a few lines of code.

Explore our docs
  instruction: 'Draw a bounding box around all the cars in the image.',
  attachment: '',
  objects_to_annotate: ['car'],
  callback_url: '',
}, (err, task) => {
  // do something with task

We Are Scalable

We are built to handle millions of requests per month. Scale is powered by our distributed team of hard-working Scalers augmented with machine learning technology.

Our effective screening, training, and routing software help ensure that we deliver only the highest quality at scale.


Scale is trusted by world-class companies.

The world's best and most innovative companies use Scale to power large-scale human operations. We consistently impress with our incredible quality and cost effectiveness.


You only pay for what you use. There are no additional costs or termination fees.

Pay as you go!

Use Case1 Day Response1 Week Response
Bounding Box, Polygon, & Line$0.100 + $0.100 / annotation$0.080 + $0.080 / annotation
Point Annotation$0.100 + $0.050 / point$0.080 + $0.040 / point
Semantic Segmentation$8.000 / image$6.400 / image

Completion times are best-effort for non-enterprise users. If you have more than 1000 requests per month or require a task completion time SLA, chat with us about Enterprise Plans!

We’ll even give you 5 free API calls. Create free Account


Custom annual plans for high volume.

  • Upfront and Volume Discounts
  • Enterprise-grade SLAs
  • 24/7 Development Support
  • Dedicated Account Managers