DataAnnotation vs Alignerr vs Mercor: Key Differences
A sourced, side-by-side comparison of three platforms that hire developers for AI training work — work types, application process, requirements, location and pay information.
By Software Side Hustles Editorial Team · Published · Updated · 4 min read
All three platforms pay contributors to help train and evaluate AI, and all three have work for people with coding skills. They differ in how you apply, how work is matched and what they publish about requirements.
Everything below comes from each platform's public pages, checked on 12 October 2026. Platforms change their processes; always confirm on the official site. We are not affiliated with any of them.
At a glance
| DataAnnotation | Alignerr | Mercor | |
|---|---|---|---|
| How it describes itself | Remote contract roles training AI | "Where experts get paid to train AI", powered by Labelbox | "Organizing human intelligence to power the AI economy" |
| Coding work | Dedicated Software Engineer and related engineering roles | A Coding category of listings | Engineering expert roles; software engineering benchmark work (APEX-SWE) |
| How you get work | Choose a qualification track; take a Starter Assessment | Apply to individual job listings | Apply to specific listings and contracts |
| Assessments | Starter Assessment, which the FAQ says can only be taken once | Some projects add a Zara AI interview or domain-specific assessment | AI interview and assessments are documented |
| Identity checks | Not described on the pages we checked | Phone verification and ID verification via Persona | ID verification via Persona; background checks for some projects |
| Location | Eligible countries not listed publicly | Not listed publicly; payment setup depends on location | Region-specific listings; unspecified listings presumed open to the US, Canada, UK and EU |
| Published pay information | Coding roles listed at "up to $40–$150+/hr" | Pay shown on each listing | Pay set per listing/contract |
| Payments | PayPal (FAQ) | Stripe Connect or PayPal, depending on location | Stripe Connect, or Wise where Stripe is unsupported |
DataAnnotation
What the coding work looks like. The Software Engineer listing describes working with frontier models on real tasks, analysing the AI's work against production standards and red-teaming models to expose "unsafe code, faked test passes, and confidently wrong solutions".
Requirements. The listing asks for professional or serious open-source experience shipping production code, comfort in at least one major stack, and clear written English. It states no degree is required for this role. The general FAQ requires all workers to be fluent in English.
Process. You pick a qualification track by selecting a Starter Assessment. The FAQ says it can only be taken once, and that most assessments take about an hour (specialised ones one to two hours).
Things to know. The FAQ states there are no minimum hours, and that work availability depends on demand for your skills and your past performance.
Sources: homepage, FAQs, Software Engineer listing. Our guide: DataAnnotation.
Alignerr
What the work looks like. Alignerr is branded "powered by Labelbox". Its homepage lists work such as evaluating AI answers and search results and writing domain tasks, with a Coding category among its listings.
Process. Its process page describes signing up with Google and uploading a résumé, applying to listings (each showing requirements and pay), phone and Persona ID verification, contract and payment setup, and onboarding. Some projects require a Zara AI interview or a domain-specific assessment.
Things to know. The process page asks you to check that your profile location is correct, and says payment setup (Stripe Connect or PayPal) depends on location.
Sources: homepage, process, FAQs. Our guide: Alignerr.
Mercor
What the work looks like. Mercor works with AI companies on human evaluation, data and benchmarks, including APEX-SWE, described as real-world software engineering tasks. Its network includes engineers among other professionals.
Process. Mercor's talent documentation covers account creation with passwordless email verification, applying to listings, an AI interview, assessments, Persona ID verification and project onboarding (which can include Insightful time tracking).
Location. Mercor's referral documentation states that region-specific listings accept only candidates from that region, and that listings without a stated location are presumed available to applicants in the United States, Canada, the United Kingdom or the European Union. A separate page lists countries where Mercor can pay experts.
Sources: homepage, talent docs index, referral policy, supported payment countries. Our guide: Mercor.
Which should you try first?
There is no universally "best" platform. A few practical heuristics:
- You have production engineering experience and want dedicated coding tasks: DataAnnotation's coding roles are described most specifically. Remember the single-attempt Starter Assessment — prepare first.
- You prefer to choose individual projects: Alignerr and Mercor are both listing-based, so you can apply to work that matches your stack.
- You are outside the US, Canada, UK and EU: check each Mercor listing's region, and confirm DataAnnotation and Alignerr availability for your country directly.
You can apply to more than one. Our questionnaire compares your answers with each platform's published requirements and flags anything you should check.
A note on referral links
Some links to these platforms on our site may be referral links, and we may be compensated if you are accepted through them. Platform cards always say which kind of link you are using, and every guide includes the ordinary application route. See our Affiliate Disclosure.