The independent guide to RLHF companies

Pairwise preferences, reward model data, SFT demonstrations, and the platforms to run them yourself. Filter by workload, buying model, and published security evidence, with every fact linked to its source.

Explore the landscape Read the buyer’s guide

20vendors profiled: Managed services, expert networks, platforms, and dataset sellers.
68primary sources: Vendor sites, trust portals, and company releases. No listicles.
0paid placements: Nobody pays to appear or to change their position.

Who covers what

Filter vendors

Published workload coverage for 20 RLHF vendors. Click a column to see those vendors.

Which workloads each vendor publicly describes
Vendor	Preference & ranking	SFT demonstrations	RLHF & reward data	Expert raters	Evals & red teaming	Reasoning & RL	Run your own	Multimodal
Appen	Yes	Yes	Yes	Yes	Yes	Yes	No	Yes
Cogito Tech	No	Yes	Yes	No	Yes	No	No	No
Encord	Yes	No	Yes	No	Yes	No	Yes	Yes
Handshake AI	No	No	No	Yes	No	Yes	No	No
HumanSignal (Label Studio)	No	No	Yes	Yes	Yes	No	Yes	No
iMerit	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Innodata	Yes	Yes	Yes	No	Yes	No	No	No
Invisible Technologies	No	No	No	Yes	Yes	No	No	Yes
Kili Technology	Yes	Yes	Yes	Yes	No	Yes	Yes	No
Labelbox	Yes	No	Yes	Yes	Yes	Yes	No	No
Mercor	No	No	No	Yes	Yes	No	No	No
Patronus AI	Yes	No	No	Yes	Yes	Yes	No	No
Prolific	Yes	No	No	Yes	Yes	No	Yes	No
Sama	Yes	No	No	No	Yes	No	No	Yes
Scale AI	Yes	Yes	Yes	Yes	Yes	No	No	Yes
Snorkel AI	Yes	Yes	No	Yes	Yes	Yes	No	No
SuperAnnotate	Yes	Yes	Yes	No	Yes	No	Yes	No
Surge AI	No	No	No	Yes	Yes	Yes	No	No
Toloka	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes
Turing	No	No	Yes	Yes	Yes	Yes	No	Yes
Vendors	12	9	11	15	18	10	7	8

Based on each vendor’s published categories and capabilities. A filled dot means the vendor describes this workload publicly; it is not a quality judgment.

Vendor landscape

20 vendors, checked November 8, 2026. Filter by workload, buying model, published certifications, and public pricing. Select up to four to compare side by side.

RLHF vendors in alphabetical order with buying model, ownership, published certifications, and pricing
Vendor	Buying model	Ownership	SOC 2	ISO 27001	HIPAA	GDPR	Pricing
AppenManaged RLHF & SFT data	Managed service, Off-the-shelf datasets	Publicly listed	Published	Published	Not found	Published	On request
Cogito TechManaged RLHF & SFT data	Managed service	Privately held	Published	Not found	Published	Published	On request
EncordAnnotation platform	Managed service, Platform you operate	Privately held	Published	Not found	Published	Published	On request
Handshake AIExpert network for AI training	Expert network	Subsidiary	Published	Not found	Not found	Published	On request
HumanSignal (Label Studio)Annotation platform (open source and self-serve)	Managed service, Platform you operate	Privately held	Published	Not found	Published	Not found	Published
iMeritManaged RLHF & SFT data	Managed service, Platform you operate	Subsidiary	Published	Published	Published	Published	On request
InnodataManaged RLHF & SFT data	Managed service, Off-the-shelf datasets	Publicly listed	Not found	Not found	Not found	Not found	On request
Invisible TechnologiesManaged post-training data	Managed service, Expert network	Privately held	Published	Not found	Published	Published	On request
Kili TechnologyAnnotation platform (self-serve and enterprise)	Managed service, Platform you operate	Privately held	Not found	Not found	Not found	Not found	Published
LabelboxManaged expert data	Managed service, Expert network	Privately held	Published	Not found	Published	Published	On request
MercorExpert network for AI training & evals	Expert network	Privately held	Published	Not found	Not found	Not found	On request
Patronus AIManaged RL environments & post-training data	Managed service	Privately held	Published	Not found	Published	Not found	On request
ProlificSelf-serve participant platform	Managed service, Platform you operate	Privately held	Not found	Published	Not found	Published	Published
SamaManaged annotation & preference data	Managed service	Privately held	Published	Published	Not found	Published	On request
Scale AIManaged RLHF & post-training data	Managed service	Privately held	Published	Published	Not found	Not found	On request
Snorkel AIManaged expert data (data-as-a-service)	Managed service, Expert network	Privately held	Published	Not found	Published	Not found	On request
SuperAnnotateAnnotation platform	Managed service, Platform you operate	Privately held	Published	Published	Not found	Published	On request
Surge AIManaged expert post-training data	Managed service, Off-the-shelf datasets	Privately held	Not found	Not found	Not found	Not found	On request
TolokaManaged post-training data	Managed service, Platform you operate	Privately held	Published	Published	Published	Published	On request
TuringExpert human data for post-training (coding, STEM, multimodal)	Off-the-shelf datasets	Privately held	Published	Not found	Not found	Not found	On request

Alphabetical. A check means the vendor publishes it on its own site or trust portal; a dash means we found nothing public, so ask the vendor.

Research and comparisons

GuideNov 8, 2026 How to choose an RLHF or preference data vendor Seven decisions, in order: training method, preference format, raters, calibration, buying model, security evidence, and commercial terms. ComparisonNov 8, 2026 HumanSignal vs Kili Technology ComparisonNov 8, 2026 Appen vs Innodata ComparisonNov 8, 2026 Scale AI vs Surge AI

Browse by workload

How this guide works

Every claim links to a public source, with the date we checked it.
No paid rankings. Vendors are listed alphabetically or by the filters you choose.
Pricing shown only where a vendor publishes it. Otherwise: contact vendor.

Read the methodology