Something shifted in the AI labeling industry around 2024. Frontier labs ran out of easy gains from million-row Mechanical Turk annotations. The next jump in model quality had to come from a hundred radiologists rating cancer outputs, fifty patent attorneys building legal reasoning chains, or twenty mathematicians writing proofs the model could not paper over. A PhD became worth more than a clever screenshot prompt.
That shift is why this list exists. Pay at the bottom runs about $40 per hour for general expert work. At the top it reaches $300 per hour for narrow medical, legal, and frontier-research specialists. The 13 platforms below are the ones we have either applied to ourselves, watched contractors get paid by, or pulled first-party application data from over the last 18 months at RemoWork's company directory.
At a glance
Pay floor
$40/hr
Top tier
$300/hr
Time to first task
2 to 10 days
Remote-friendly
All 13
Who this guide is for
People who already hold a credential these platforms gate for: a PhD or ABD candidate, a postdoc, an MD, a JD, a senior research engineer with 5+ years in one specialty, or a published expert in a verifiable domain. Still in undergrad or learning your first language? Start with our general AI training listicle, build a track record, and come back.
One honest note
Many platforms below say "PhDs preferred" in marketing copy but accept master's holders or senior engineers with deep portfolios. If you are close to the credential bar, apply anyway. The vetting process tells you the truth faster than the marketing page does.
How we ranked them
We score every platform on five things: verified top-end pay (with evidence, not marketing copy), realistic time-to-first-task after acceptance, how brutal the vetting is, payout reliability based on contributor reports, and the depth of the customer roster. The team behind this article maintains the company-directory side of RemoWork.life, which means we pull founder names, funding history, and hiring-page changes weekly. We applied to seven of the 12 platforms below ourselves and cut three from earlier drafts because pay claims did not match what contributors actually saw.
The ranking is not strictly "highest pay first." A platform paying $250 per hour means little if you wait six months for your first task. We weight the realistic onramp as heavily as the ceiling.
July 2026 update: We removed Defined.ai from this list. The company has pivoted to B2B dataset licensing, no longer promotes its contributor arm, and the surviving Neevo portal is low-pay microtask work with credible nonpayment complaints, so it no longer meets the bar for a list about paying PhDs. We also added Handshake AI, Alignerr, and Braintrust, and updated Mindrift for its July 2026 merger with Toloka.
The 13 platforms ranked
AfterQuery
AfterQuery is the highest-leverage option on this list if you can clear vetting. Founded in January 2025 by three Wharton and Penn graduates, it closed a $30M Series A at a $300M valuation in April 2026, led by Altos Ventures with The Raine Group, and reportedly passed a $100M revenue run-rate within 16 months. The network is roughly 100,000 verified professionals across finance, law, medicine, engineering, software, ML, business, and health.
Pay range
$40–$250+/hr
Time to first task
5–10 days
Credential
PhD / MD / JD
Best for
Top-tier specialists
Key detail: Pay tiers run $40–$50 for general expert work, $80–$150 for specialist tracks, and $150–$250+ for the top tier; NVIDIA was publicly named as a client engagement in July 2026. Payments go out every Friday through Stripe to bank accounts only (no PayPal), with a 7-day hold on the first payout and no minimum. Stripe covers 100+ countries including Kenya, India, and South Africa, but excludes Nigeria, Brazil, Egypt, and Ghana, so check the payout list before investing time in vetting. Apply at experts.afterquery.com, and read our first-hand AfterQuery review before you do. The catch: vetting is harder than the marketing page implies, work arrives in project waves rather than a steady queue, and there is no documented appeal process for rejected tasks.
Handshake AI
Handshake AI is the AI-training arm of the established career platform Handshake, recruiting students, graduates, and domain experts to train frontier models for leading AI labs. It is arguably the most credential-sensitive platform on this list: your degree is the product, and the pay bands are explicitly tiered by it. No prior AI experience is required.
Pay range
$30–$300+/hr
Time to first task
Days to weeks
Credential
Degree-tiered pay
Best for
PhDs, MDs, JDs, finance
Key detail: Master's and PhD holders earn $30–$150/hr, and specialists in medicine, law, and finance reach $175–$300+/hr, the highest verified ceiling on this list. Projects run weeks to months with flexible hours and weekly pay. The catch: content you create belongs to Handshake and its partner labs, and there are contributor reports of payment withholding and account suspensions, so keep your own work records.
Aligned Labs
Aligned Labs runs the contributor portal at alignedhq.ai with a network of about 5,000 experts from MIT, Stanford, Harvard, and peer institutions. Founded in 2024 in San Francisco by Paul McDonald (ex-Google), it supplies frontier labs (OpenAI is a publicly confirmed customer) across 11 academic domains: biology, chemistry, computer science, economics, engineering, finance, law, mathematics, medicine, physics, and psychology. It is recruiting hard right now for physics, chemistry, biology, materials science, neuroscience, dermatology, radiology, ophthalmology, and otolaryngology.
Pay range
$50–$150+/hr
Time to first task
7–14 days
Credential
PhD, hard sciences
Best for
Physics/chem/bio/med PhDs
Key detail: Aligned does not publish fixed hourly bands; you set your target rate during onboarding and the company matches you to projects in your range. Apply at alignedhq.ai. The catch: the rate-setting model means your first offer may be lower than you expect. Hold your number; if your domain is truly scarce they come back.
Meridial AI
Meridial is the expert marketplace operated by Invisible Technologies, with roughly 24,000 vetted domain experts working on AI training for customers like Microsoft, Nasdaq, Cohere, AWS, and AI21 Labs. Compliance is unusually strong for a marketplace at this stage: SOC 2, HIPAA, and GDPR are all in place, which makes it one of the few options for medical and finance specialists who care about how their data flows.
Pay range
$6–$65/hr
Time to first task
~2 days
Credential
Verified domain expert
Best for
Multi-domain experts
Key detail: Student and general trainer roles run $15–$20/hr; specialist tracks (literature, anthropology, STEM, legal reasoning, AI safety, creative writing) range $6–$65/hr. Apply at meridial.ai/projects; qualified experts can review invitations within 48 hours. The catch: domain mismatch is the top reason for low offers, so list every specialty you can credential during onboarding.
Mercor
Mercor is the platform you have probably heard about because its three co-founders (Brendan Foody, Adarsh Hiremath, Surya Midha) became some of the world's youngest self-made billionaires at 22. The company closed a Series D at a $10B valuation in 2025 and uses that capital aggressively to recruit PhDs. Specialist tracks run $20–$100/hr, with elite roles documented as high as $200/hr.
Pay range
$20–$200/hr
Time to first task
Often <72 hrs
Credential
Strong public profile
Best for
ML / research engineers
Key detail: Mercor pulls signals from your LinkedIn, GitHub, and Google Scholar within minutes of signup, then schedules an AI-led video interview. Read our full Mercor review for the interview transcript. The catch: the signal screen rejects more than 80% of applicants on the first pass, including some strong candidates. A bare LinkedIn does not work here.
Outlier (by Scale AI)
Outlier is the contributor side of Scale AI and the largest network on this list, reportedly 700,000+ master's, PhD, and senior-credentialed contributors worldwide. Pay is tiered: general contributors $15–$50/hr, specialist tracks $30–$100/hr, PhD tracks $50–$100+/hr. Payouts go out weekly on Tuesday via Hyperwallet for work completed in the prior cycle.
Pay range
$15–$100+/hr
Time to first task
~7 days
Credential
Master's / PhD tiers
Best for
Cadence over peak
Key detail: The platform is mature, the payout pipeline is reliable, and task availability is more consistent than at faster-growing competitors. Read the Outlier review for the full task-availability breakdown. The catch: task volume fluctuates aggressively by domain. A coding-track contributor may have 30 hours this week and three the next. Plan around it.
Alignerr
Alignerr (backed by Labelbox) specializes in exactly the work PhDs are best at: cognitive labeling, reasoning refinement, bias identification, and red-teaming. It explicitly recruits PhDs, researchers, and subject-matter experts, advertises an average around $80/hr, and accepts applicants globally, which makes it one of the strongest expert options outside the US.
Pay range
$25–$150/hr
Time to first task
1–3 weeks
Credential
PhDs, researchers, SMEs
Best for
Global expert access
Key detail: Domain experts earn $35–$125/hr and roughly 20% of trainers clear $90+/hr; onboarding runs through the "Zara" AI interviewer plus assessments and a background check. The catch: project availability is inconsistent, so treat it as high-rate supplemental income rather than a full-time pipeline.
Braintrust
Braintrust is a user-owned talent network whose AI-training vertical publishes its rate bands openly, rare in this industry: expert evaluation $60–$150/hr, red teaming $50–$120/hr, and AI code review $75–$200/hr. Freelancers keep 100% of earnings (no platform fee) and are paid weekly. Screening is a 15–20 minute AI-led video interview.
Pay range
$20–$200+/hr
Time to first task
~7 days
Credential
Professional expertise
Best for
Devs, doctors, lawyers
Key detail: Apply at usebraintrust.com/ai-training. The catch: eligibility is region-limited to the US, Canada, UK, EU, Mexico, Brazil, India, Japan, South Korea, and Singapore. Africa is currently excluded, so contributors there should look at OpenTrain, which pays into Kenya and Nigeria, instead. Alignerr now blocks Kenya too, and Pareto wound down in October 2026.
OpenTrain
OpenTrain is the rare AI training marketplace that publishes its per-role rates publicly before you apply. Founder and CEO Weston Dotson built the company around contract transparency: employers pay the platform fee (10% self-service or 20% managed), freelancers pay nothing, and the network now counts 254,000+ trainers across 190+ countries. It works like an Upwork for AI training: you bid on listed contracts rather than waiting for an assignment queue.
Pay range
$30–$100/hr
Time to first task
~5 days
Credential
Track-dependent
Best for
Rate transparency
Listed role rates (verified July 2026)
- Code Review Specialist: $75/hr
- LLM Hybrid-RLHF: $72/hr
- RLHF Red Teaming: $65/hr
- Medical Data Review: $55/hr
- Math Reasoning Evaluator: $45/hr
- Content Safety / Data Labeling: $28–$36/hr
Key detail: Payments run through Stripe on a milestone-escrow model (the client funds work upfront), with payouts to 140+ countries including Nigeria, Kenya, India, and the Philippines. Apply at opentrain.ai/become-freelancer. The catch: it is a marketplace, not an assignment queue; income depends on winning contracts, and contributor reviews include slow client communication alongside the confirmed payouts.
Mindrift
Mindrift became Toloka's single contributor platform in July 2026, when Toloka folded its entire classic crowd into it; the old Toloka contributor site now redirects here, and existing accounts, balances, and history migrated automatically. Before the merger, Mindrift's expert network was about 20,000 trainers with roughly 70% holding a master's degree or PhD, covering 90+ domains and 20+ languages, with the top end reserved for medical, legal, and senior STEM tracks. Toloka is a Nebius Group company whose 2025 funding round was led by Bezos Expeditions, and Mindrift operates from Switzerland, which matters if you care about EU data-protection compliance.
Pay range
$15–$100+/hr
Time to first task
~10 days
Credential
~70% MA / PhD
Best for
Multi-domain PhDs
Key detail: Apply at mindrift.ai; the vetting includes a domain test that adapts to the specialty you select at signup, and rewards are adjusted by a country cost-of-living index. Read our Mindrift review for the test breakdown. The catch: project availability is uneven, and the July 2026 merger folded the migrated general crowd into the same platform, so expect more competition for general evaluation tasks.
SME Careers (SuperAnnotate)
SME Careers is SuperAnnotate's expert recruiting brand. SuperAnnotate, founded in 2018 in Yerevan, Armenia, raised $50.5M across Series A and B, and is one of the few annotation platforms whose founders (the Petrosyan brothers plus two co-founders) all dropped out of PhD programs themselves. That cultural detail shows up in how the platform treats domain experts.
Pay range
$20–$130+/hr
Time to first task
~10 days
Credential
Selective written task
Best for
Writers + STEM
Key detail: Pay is published openly at $20–$130+/hr, and payouts are weekly. Vetting is a written task instead of an AI interview, with an acceptance rate comparable to Mercor's signal screen. The catch: SuperAnnotate's main revenue is the SaaS annotation platform, so SME Careers is sometimes deprioritized when the enterprise pipeline is busy. Availability mirrors their B2B sales calendar.
DataAnnotation.tech
DataAnnotation is the contributor brand of Surge AI, founded in 2020 by Edwin Chen (ex-Google, ex-Meta). Surge has built a small empire of expert-labeling brands, and DataAnnotation specifically is the writer and STEM-credential track. Glassdoor rates the contractor experience 4.0 from 158 reviewer reports.
Pay range
$20–$75/hr
Time to first task
~7 days
Credential
STEM gated for top
Best for
Coders + writers
Key detail: Pay by track: general $25–$30/hr, multilingual $20–$30/hr, coding $50–$75/hr, STEM (master's or PhD gated) $40+/hr. Read our DataAnnotation review. The catch: the platform is notorious for unexplained account bans, so keep a record of your work history off-platform too.
Terac
Terac is the youngest platform here, founded in 2025 in San Francisco by Zachary Baker and Jack Blair on a $9M seed from Antigravity Capital. The network is roughly 100,000 vetted experts serving market-research clients like Maze, Strella, Tegus, Ballpark, getWhys, and Dialogue, plus AI labs running evaluation work. Trustpilot and Google both rate Terac 5.0 from real reviewer reports, which is rare in this category.
Pay range
$24–$150/hr
Avg across studies
$78/hr
Time to first task
~7 days
Best for
Research interviews
Key detail: Typical participant tier runs $24–$40/hr; senior specialist and deep-interview engagements pay $50–$150/hr. Apply at terac.com. The catch: study cadence is set by client demand, so a great profile may sit unused for a few weeks if your domain has no live studies.
At-a-glance comparison
| Platform | Pay range | Time to first task | Best for | The catch |
|---|---|---|---|---|
| AfterQuery | $40 to $250/hr | 5 to 10 days | Top-tier specialists | Hard vetting |
| Handshake AI | $30 to $300+/hr | Days to weeks | PhDs, MDs, JDs, finance | IP belongs to labs |
| Aligned Labs | $50 to $150+/hr | 7 to 14 days | Hard sciences PhDs | Hold your rate |
| Meridial AI | $6 to $65/hr | 2 days | Multi-domain experts | List every specialty |
| Mercor | $20 to $200/hr | 3 days | Strong public profile | 80%+ rejection rate |
| Outlier | $15 to $100/hr | 7 days | Cadence over peak | Volume fluctuates |
| Alignerr | $25 to $150/hr | 1 to 3 weeks | Global expert access | Uneven availability |
| Braintrust | $20 to $200+/hr | 7 days | Published rate bands | No Africa access |
| OpenTrain | $28 to $100/hr | 5 days | Rate transparency | Bid-based marketplace |
| Mindrift | $15 to $100+/hr | 10 days | Multi-domain PhDs | Uneven projects |
| SME Careers | $20 to $130+/hr | 10 days | Writers + STEM | B2B cycle ties |
| DataAnnotation | $20 to $75/hr | 7 days | Coders + writers | Random bans risk |
| Terac | $24 to $150/hr | 7 days | Research interviews | Demand-driven |
How to choose between them
Pick by your specialty first, by your priority second. These three profiles cover most readers of this list.
Hard-science PhD
Physics, chemistry, biology, neuroscience, materials science, or radiology? Start with Aligned Labs, Handshake AI, and Mindrift. All three index hard for those domains and pay accordingly.
JD, MD, or finance PhD
AfterQuery's top tier is realistically reachable, Handshake AI pays specialists $175 to $300+/hr, and Meridial's compliance stack suits regulated data. Lead with the rarest credential you hold.
ML / research engineer
Strong public artifacts (papers, GitHub, model checkpoints)? Apply to Mercor first; the signal screen rewards exactly that. Braintrust (AI code review at $75 to $200/hr) and SME Careers are the higher-ceiling backups.
If you care about cadence and predictability, Outlier and OpenTrain are the safer bets. If you want the highest possible per-hour rate and you are willing to wait through harder vetting, AfterQuery and SME Careers are the swing for the fences. If you are based outside the US or EU and worried about acceptance, OpenTrain, which pays into 140+ countries including Kenya and Nigeria, gives you the best odds. Meridial's country lists are wide but leave out Kenya and Ethiopia, and Pareto, once the Africa-first option, wound down in October 2026. Apply to three or four in parallel: vetting times are unrelated, projects do not overlap, and you give yourself optionality once offers land.
How to actually get approved faster
Mirror the job
Write your application essay like a job posting in reverse. If the platform's customer wants "RLHF specialists with medical reasoning," use that exact vocabulary: RLHF, chain-of-thought, evaluation rubric, edge cases. Reviewers pattern-match at scale; be the easiest pattern to confirm.
Link your evidence
A bare claim of a PhD in biophysics is weaker than a Google Scholar link with three papers and a GitHub gist of a recent analysis. Even a personal Notion page works. Platforms want to compress vetting time, and they pay people who make that easy.
Lead with the rarest credential
JD plus a CS master's? Lead with the JD; the pool is smaller. PhD plus fluency in Mandarin? Lead with both, because the intersection is exactly where platforms pay the top specialist rate.
Frequently asked questions
Do I need a PhD, or is a master's enough?
A master's is enough for most platforms on this list, as long as your specialty is in demand. Handshake AI, Mercor, OpenTrain, Mindrift, Outlier, Alignerr, Braintrust, SME Careers, and DataAnnotation all accept master's holders. AfterQuery, Aligned Labs, and Meridial's top tiers tend to filter harder toward PhDs in narrow domains.
Are these 1099 contractor or W-2 roles?
All 13 are 1099 independent contractor arrangements for US-based contributors, with equivalent self-employed status outside the US. None offer health insurance, paid time off, or employer-side payroll tax contributions. If you live in the US, expect to set aside roughly 25 to 30% for federal plus self-employment tax.
Do any of them require US citizenship?
None require US citizenship as a hard rule. Some specific projects (especially government-adjacent or US-defense-related work on AfterQuery, Aligned Labs, or Mercor) require US work authorization due to client compliance, but those are project-level constraints, not platform-level. International contributors can join most of the 13, but not from everywhere: Handshake AI expects US work authorization, Mercor works only with the 107 countries on its supported-countries list, and Outlier only from the 117 places on its working-location policy. Neither of the last two includes Kenya or Pakistan. Beyond that, the main practical issue is payout method. AfterQuery pays through Stripe to bank accounts in 100+ countries but excludes Nigeria and Brazil, while OpenTrain pays into 140+ countries including Nigeria and Kenya, so check the payout list before you invest time in vetting.
How much can a PhD realistically earn per month?
Based on contributor reports we have aggregated, a vetted specialist working 10 to 15 hours per week sustainably across two or three platforms earns roughly $2,000 to $5,000 per month. Top earners in narrow medical and legal specialties working full-time hours have reported $12,000 to $20,000 per month, but those are outliers, not the median. Treat anything above $8,000 per month as exceptional rather than expected.
Which platform pays the fastest?
Outlier (weekly on Tuesday via Hyperwallet) and Mercor (within 24 to 48 hours of task completion via Stripe Connect or similar) are the fastest. AfterQuery, Handshake AI, Braintrust, and SME Careers all pay weekly; AfterQuery's cycle lands every Friday, with a one-time 7-day hold on your first payout. Most others pay biweekly or weekly.
Ready to put your credentials to work?
Browse live remote AI training and research roles from these platforms and dozens more in the RemoWork directory.
Browse Remote AI JobsThe story to remember from this list is the 2024 shift. Frontier AI labs decided they could not climb the next quality curve with cheap labelers, so they opened budgets for specialists. The 13 platforms above are the ones that built around that thesis early. If you have the credentials, you are in a rare moment where the demand side genuinely needs you, and the rates reflect it. Bookmark this page. We refresh it every 90 days as platforms launch new tracks and change rates.
Related reading: Top AI Training Platforms That Pay You to Train AI Models in 2026 · Pila8 Review · Mercor Review · Outlier AI Review
