Sigma AI Review 2026: What the Vendor Actually Says

By Mufy Pachorawala, founder of getAIwork · Last updated: September 24, 2026

Sigma AI is a real Madrid-based data annotation vendor with 79 live freelance postings across 99 countries, and it publishes no pay information whatsoever. Not a rate, not a threshold, not a processor, not a schedule. We checked all 79 postings and every legal page. It also tells you three different things about its own age and three about its own size.

Key facts, checked September 23 and 24, 2026

  • 79 live postings on its Teamtailor careers feed, newest September 23, 2026, oldest June 3, 2024
  • 0 of 79 mention pay. No rate, no currency, no baseSalary in the structured data
  • 99 countries in the postings, led by the UK (45), the US (31) and India (23)
  • Engagement model: its own wording is “offered for freelancers under a commercial contract”
  • The careers site is unreachable from sigma.ai. Not in the footer, not in the sitemap, not in llms.txt
  • Company age is published three ways: 30 years, 18 years, and founded 2008
  • Our own board currently carries 1,662 live AI listings, free and public at getaiwork.com/board/

What is Sigma AI?

Sigma AI is a data collection and annotation vendor. It gathers, labels and evaluates speech, text and image data for companies building AI models, and it staffs that work with freelancers recruited by language and country. Its privacy notice names the operating entity as SIGMA. AI, SLU, registered at Avenida de Burgos 114 in Madrid, and states plainly that the group holding company is American and based in Miami. Its about page credits the founding to Daniel Tapias and Nuria Gomez in 2008, with offices in Madrid, London and Miami.

If you have worked for Appen, Welocalize or TELUS, the shape is familiar: you apply to a specific language project, you pass an assessment, you work when that project has volume, and you go quiet when it does not. What is different about Sigma is how little of that it writes down.

A freelance annotator working at a laptop

How much does Sigma AI pay?

It does not say. That is the honest answer and it took some work to be confident about it. On September 23, 2026 we pulled the complete JSON feed from its careers site, all 79 live postings and their full body text, and scanned every one of them for PayPal, Payoneer, Wise, bank transfer, per hour, hourly rate, per task, salary, compensation, remuneration, payout, threshold, invoice, and every currency symbol. Zero postings matched anything. The Schema.org JobPosting blocks carry a baseSalary field on none of them.

The legal pages are no better. The terms and conditions cover website use and never use the words freelancer, contributor, payment or compensation. The data protection page, which is the privacy document, never mentions workers, annotators, candidates or recruitment at all, which is a strange omission for a company running an applicant tracking system. And the FAQ page carries the heading “What is Sigma’s pricing model?” with no answer text underneath it.

What this means in practice. You cannot compare a Sigma project against another platform before you apply, because there is nothing to compare. The rate, if there is one, appears somewhere inside the application flow after Sigma has your details. That is a choice, and other vendors in this category make the opposite one. DataForce publishes exact dollar figures per project. Clickworker publishes its payout thresholds to the euro. Sigma publishes neither.

How do you actually apply to Sigma AI?

At careers.sigma.ai, and that is the whole trick. From sigma.ai itself, /careers, /jobs, /work-with-us, /join and /collaborators all return 404. The sitemap has 36 URLs and none of them is a careers page. The llms.txt file lists seven pages and no careers entry. The homepage footer has no careers link. The only way to reach the front door of Sigma AI as a worker is to find it in a search engine, which is an odd thing for a company that needs freelancers in 99 countries.

Once there, applying is a Teamtailor form. The postings say you will hear back by email and to check your spam folder. The engagement wording is consistent across the board: “This opportunity is offered for freelancers under a commercial contract.”

Hardware you need, which Sigma does publish

  • A computer with at least 4GB RAM
  • Windows 10 or higher, or macOS 13 Ventura or higher
  • For audio collection projects only, an Android phone
  • Tablets and iOS devices are not supported
A job application form on a screen

Where Sigma’s own pages disagree with each other

This is the part worth reading twice, because every line below comes from a page Sigma controls, and several of them are live simultaneously.

Claim One Sigma page says Another Sigma page says
Years in business 78 of 79 job postings: “over 30 years of experience” Homepage: “18+”. About page: founded 2008
Crowd size Homepage and llms.txt: “70,000+ vetted experts” About page: “25K+ annotators, linguists, project managers”
Languages Homepage: “700+”. 71 of 79 postings: “more than 700 languages” About page: “500+”. 5 postings dated September 11, 2026: “more than 200 languages”
Governing law Terms and conditions: California law No California office, entity or address appears anywhere on the site
Pricing model FAQ asks the question FAQ publishes no answer

All checked September 23 and 24, 2026. The 200-language and 700-language postings were live on the same job board on the same day, twelve days apart in posting date.

None of this makes Sigma a scam. Marketing copy drifts, pages get rebuilt, nobody audits the boilerplate at the bottom of a job posting. A 1996 founding date on a company founded in 2008 is the kind of thing that happens when someone rounds up in a template and nobody checks for three years. But when a vendor will not tell you what it pays, the care it takes with its other published facts is most of the evidence you have, and this is not a lot of care.

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How Sigma AI compares to the vendors it competes with

Vendor Publishes a rate? Publishes a payout threshold? Names a processor? Signup route
Sigma AI No, 0 of 79 postings No No Teamtailor, unlinked from its own site
DataForce by TransPerfect Yes, exact dollars per project Wire transfer over $50 only Yes, five named Community subdomain
Clickworker No site-wide rate Yes, five thresholds published Yes, five named Direct signup
Prolific Yes, a published floor rate Yes Yes, PayPal Direct signup
Appen and CrowdGen Yes, on individual postings Fee-based hold, value not published Yes, via Dots CrowdGen signup

Read that table as a disclosure ranking rather than a quality ranking. A vendor that publishes its rates is not automatically paying more. It is telling you more, which is a different and smaller thing, and it is still the only thing you can check before you spend an evening on an assessment.

A team reviewing data on a monitor

Is Sigma AI worth applying to?

Apply if you fit a live language project and you treat it as one of several queues, not your main one. Sigma is a genuine vendor with genuine volume, and 99 countries is broader coverage than most of its competitors offer. But go in knowing you will not see a rate until you are deep in the process, and cap the unpaid time you spend qualifying. Four hours is a reasonable ceiling for any vendor that will not tell you what the work pays.

One practical note. Sigma’s board carries postings more than two years old, still live and still accepting applications. The oldest is a Lithuanian linguistics project from June 3, 2024. An old posting is not necessarily a dead one in this category, because vendors keep language pools open against future contracts, but it does mean the posting date tells you nothing about whether there is work today. Ask that question directly before you start an assessment: is there live volume on this project right now, and what is the expected weekly hours range. A vendor with real work answers it.

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Frequently asked questions

Is Sigma AI legit?

Sigma AI is a real company. Its privacy notice names the legal entity as SIGMA. AI, SLU, a Spanish company at Avenida de Burgos 114, Madrid, and states that it belongs to the SIGMA Group whose holding company is American and headquartered in Miami. Its about page says it was founded in 2008 by Daniel Tapias and Nuria Gomez. The application portal is real and live. What is missing is pay information, not legitimacy.

How much does Sigma AI pay?

Sigma AI does not publish a rate. We pulled all 79 live postings from its careers feed on September 23, 2026 and scanned every one for pay language: hourly rate, per task, salary, currency symbols, compensation, payout. Zero of 79 postings mention pay in any form, and zero carry a baseSalary field in their structured data. The vendor does not say.

Where do you sign up for Sigma AI?

At careers.sigma.ai, which is a Teamtailor careers site. You cannot get there from sigma.ai: the paths /careers, /jobs, /work-with-us and /join all return 404, the sitemap lists no careers URL, and the footer has no careers link. The only route in is a search engine.

What countries does Sigma AI hire in?

Its 79 live postings carry structured location data covering 99 distinct countries. The heaviest are the United Kingdom at 45 postings, the United States at 31, India at 23, Poland at 15 and Italy at 14. Sigma publishes no excluded-country list.

What is Sigma AI’s payout threshold?

Not published. Sigma AI publishes no payout threshold, no payment processor, no payment schedule and no holding period, on any page we could reach. Its terms and conditions cover website use and never mention freelancers or payment at all.

How old is Sigma AI really?

Its own pages give two answers. 78 of the 79 live job postings say ‘with over 30 years of experience’. The homepage says 18 or more years. The about page says the company was founded in 2008, which is 18 years. The 30-year claim would imply a 1996 founding, twelve years before the date Sigma itself publishes.

Does Sigma AI work on mobile?

Only for audio collection, and only on Android. Its postings state a minimum of 4GB RAM, Windows 10 or higher or macOS 13 Ventura or higher, and add that tablets and iOS devices are not supported.

Mufy Pachorawala

Mufy Pachorawala · Founder, getAIwork

My AI scans thousands of AI-job posts (42,827 screened so far) and I personally approve every listing before it reaches the board. I write these articles by the same rules: pay quoted only as listed, and no income promises. Read our editorial rules.

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