Comparison API

Scalable comparisons and deduplication powered by human judgment via API.

Which image looks higher quality?
Are the items in these listings the same?

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.

Accurate, Powerful Comparison

Powered by a combination of our Scaler community and machine learning, we provide actionable data via our dead-simple API.

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Cost-Effective and Flexible

We combine machine learning and our community of Scalers to solve your use cases efficiently and quickly. We're able to solve a variety of use cases, from image tagging to content moderation.

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Best-in-Class Accuracy

Scale uses a combination of skilled humans, machine learning, and sophisticated quality assurance technology to offer best-in-class accuracy. We like to surprise our customers with our high quality.

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Elegant Automation

Unlike solutions that require you to work through CSVs or build UIs, we provide automation through an easy-to-use API. It's never been easier to build human-in-the-loop apps.

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.

Comparison tasks
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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
  callback_url: '',
  instruction: 'Are the items in these listings the same?',
  attachments: [
  attachment_type: 'website',
  choices: ['yes', 'no']
}, (err, task) => {
  // do something with task

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.


Use CaseExpress Urgency
Standard Urgency
Deduplication$0.20 / Comparison$0.08 / Comparison
A/B Comparisons$0.20 / Comparison$0.08 / Comparison
Other$0.20 / Comparison$0.08 / Comparison

If you have more than 10.000 requests per month or are looking for volume discounts, turnaround SLAs, or quality SLAs, chat with us about our Enterprise Plans.

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


Custom annual plans for higher volume.

  • Upfront Custom Pricing
  • Quality and Throughput SLAs
  • Individualized Support
  • Dedicated Account Managers