Best alternatives to Scale AI for coding evaluation data in 2026
Coding evaluation data is where generalist annotation vendors break down: judging whether a Rust fix is correct or whether a Kubernetes operator handles backoff is not a task a crowd worker can rubric their way through, and the fallout from Meta's $14.3 billion investment in Scale AI (Reuters) has made that gap a live procurement question. The workload drives the shortlist: labeled code at volume, RLHF preference data from engineers, or a held-out benchmark set that resembles how developers actually solve problems. The seven credible alternatives below — HackerEarth, Surge AI, Labelbox, Appen, Snorkel AI, Toloka, and Mercor — each sit at a different point on the specialization-versus-throughput curve.
What Scale AI is used for in coding evaluation
Scale AI's role in coding evaluation sits across three overlapping workloads: generating labeled code datasets for supervised fine-tuning, collecting human preference rankings between candidate code outputs for RLHF, and building held-out evaluation suites that measure a model's coding ability against expert-written reference solutions.
Scale's product line here includes Scale Data Engine (annotation and labeling), Scale Evaluation (model benchmarking and red-teaming), and the Outlier contributor network that supplies much of its expert human labor. For code specifically, Scale is publicly described as pairing software engineering contractors with defined task workflows covering code review, bug injection, test-case generation, and preference comparisons between model-generated solutions.
The buyer here is not a recruiter. It is usually an applied ML lead at a foundation-model company, a product team fine-tuning an open-source code model, or an internal AI platform team evaluating copilots against production codebases.
Why teams look for Scale AI alternatives in 2026
Four reasons come up repeatedly in procurement conversations:
- Independence concerns post-Meta deal. Companies competing with Meta's AI efforts are hesitant to route sensitive evaluation prompts through a vendor Meta now partly owns.
- Cost at scale. Scale's enterprise contracts are opaque and often start in the six to seven figures. Smaller teams fine-tuning open-weight code models rarely clear that bar.
- Developer specialization gap. A generalist annotator pool is a weak fit for judging whether a Rust borrow-checker fix is correct, or whether a Kubernetes operator handles backoff properly.
- Data provenance and IP. For regulated buyers and enterprise ML teams, "where did this code come from, and who owns it" is a hard-stop question that favors vendors with clear contributor contracts and problem-authorship chains.
The alternatives below address at least one of these.
The seven best alternatives to Scale AI for coding evaluation data
Each entry follows the same structure: what it is, best for, key differentiator, limitations, pricing model.
1. HackerEarth
What it is: A developer skills platform with a large developer community and an assessment library covering 1,000+ skills and 40+ programming languages. In addition to hiring assessments, HackerEarth operates hackathons and coding challenges that generate large volumes of human-written, human-evaluated code under structured conditions.
Best for: Teams that need coding evaluation data where the solvers are verifiably engineers, not general crowd workers — particularly for assessing code quality across difficulty tiers with verified engineers.
Key differentiator: Problems in the HackerEarth library are authored and reviewed by problem setters rather than assembled from crowd-sourced labels on scraped code. Submissions carry correctness signals built into the challenge format (such as test-case pass rates), which can reduce the need for a separate labeling pass on some task types. The hackathon side of the business adds competitive-coding submissions from global participants, broadening the distribution of solution styles beyond what a single contractor pool typically produces.
Limitations: HackerEarth is not a general-purpose data labeling platform. If you need image segmentation, document annotation, or non-code RLHF, this is the wrong vendor. Any data partnership for ML training would be custom and scoped per engagement, not a self-serve product.
Pricing model: Custom enterprise for data partnerships. Assessment products have published tiers; data generation is scoped per project.
2. Surge AI
What it is: A high-quality human data labeling company publicly associated with RLHF work for frontier labs, as described on its own customer page. Surge recruits a smaller, more curated worker pool than legacy annotation vendors.
Best for: RLHF preference data where judgment quality matters more than volume — including code preference pairs when the task is well-scoped.
Key differentiator: Reputation for annotator quality. In conversations we have had with practitioners, teams that have moved RLHF work from Scale to Surge cite consistency and instruction-following on nuanced tasks as the main reason.
Limitations: Worker pool is smaller than Scale's or Appen's, which can constrain throughput on large coding datasets. Code-specialist depth varies by task; Surge is not developer-native the way a coding community is.
Pricing model: Per-task, negotiated by engagement.
3. Labelbox
What it is: A data labeling and model evaluation platform with a managed service arm (Labelbox Boost / Alignerr) that provides human raters for frontier model work, including code.
Best for: Teams that want a labeling platform they operate themselves, combined with on-demand expert labor when needed.
Key differentiator: Platform-plus-service model gives more control over workflow design than pure services vendors. Strong tooling for review, QA, and labeler calibration.
Limitations: Code expertise depends on which contractor pool you provision; it is not a developer community in the HackerEarth sense. Platform complexity has a learning curve for smaller teams.
Pricing model: Per-seat platform fee plus usage-based labeling costs.
4. Appen
What it is: A legacy, publicly listed data annotation company with a contributor community of more than one million experts globally, though internal full-time headcount has contracted following the Google contract loss in 2024. Appen has significant scale and multi-language reach.
Best for: Very large annotation projects where throughput and language coverage matter more than specialist depth.
Key differentiator: Scale and geographic distribution. Few vendors can match Appen's raw capacity for multi-language work.
Limitations: Quality consistency on technical tasks is a concern frequently raised in publicly available customer reviews and third-party commentary. Appen's revenue declined sharply in 2023–2024 after losing a major contract with Google (Reuters, 2024), which is worth knowing before signing a multi-year commitment.
Pricing model: Per-project, usually volume-tiered.
5. Snorkel AI
What it is: A programmatic labeling and data development platform built on weak-supervision research originating at Stanford. Snorkel uses labeling functions and model-assisted labeling to generate training data at scale.
Best for: Teams that have internal subject-matter experts and want to encode their judgment into reusable labeling functions rather than paying for annotation hour-by-hour.
Key differentiator: Programmatic approach reduces human-hour cost once the labeling functions mature. Strong fit when the evaluation criteria can be expressed as rules or model-assisted checks.
Limitations: Pure programmatic labeling struggles with the kind of nuanced judgment RLHF requires — "is this refactor cleaner" is hard to encode as a rule. Code quality assessment often still needs a human in the loop.
Pricing model: Enterprise, platform-based.
6. Toloka
What it is: A crowdsourcing platform originally built within Yandex and now operating as an independent company following its spin-out from Yandex and Nebius, effective May 2025, with a global contributor base and growing emphasis on expert-tier tasks including code and LLM evaluation.
Best for: Teams that want a flexible crowdsourcing layer with expert tiers available for coding tasks, often at lower unit cost than US-based alternatives.
Key differentiator: Flexible task design and competitive pricing. Expert-tier programs include software engineers.
Limitations: Historical association with Yandex can create procurement friction for some enterprise buyers. Code-task quality depends heavily on how tightly the task is specified.
Pricing model: Per-task, platform-driven.
7. Mercor
What it is: A talent marketplace that places vetted experts — including software engineers — on AI training, evaluation, and RLHF projects for frontier labs.
Best for: Teams that want direct access to vetted engineering contractors for code evaluation and preference-ranking work without building their own contractor pipeline.
Key differentiator: Vetting pipeline emphasizes verified professional backgrounds, which appeals to buyers who want provenance on who produced the data.
Limitations: Newer entrant with less public track record than Scale, Surge, or Appen; workflow tooling is lighter than platform-first vendors like Labelbox.
Pricing model: Per-engagement, negotiated.
Head-to-head comparison
| Platform (Scale AI shown as baseline) | Developer-native pool | Code problem library | RLHF support | Languages | Pricing model | Strongest for |
|---|---|---|---|---|---|---|
| Scale AI | Contractor network (Outlier) | Custom | Yes | Multi | Enterprise | General frontier-model data |
| Appen | 1M+ contributors | Custom | Yes | Multi | Per-project | Highest raw throughput and language coverage |
| HackerEarth | Developer community | Expert-authored library, 1,000+ skills, 40+ languages | Not off-the-shelf; custom scope | Multi | Custom | Engineer-authored problems with built-in correctness signal |
| Labelbox | Provisioned contractors | Custom | Partial | Multi | Platform + usage | Labeling platform + managed labor |
| Snorkel AI | None (programmatic) | N/A | Partial | Multi | Enterprise | Programmatic labeling |
| Surge AI | Curated worker pool | Custom | Yes | Multi | Per-task | High-quality RLHF |
| Toloka | Tiered crowdsourcing | Custom | Yes | Multi | Per-task | Cost-flexible expert tasks |
| Mercor | Vetted engineer marketplace | Custom | Yes | Multi | Per-engagement | Vetted expert contractors for code tasks |
Partial RLHF support: Labelbox provides managed human raters for preference tasks through its Boost/Alignerr service; Snorkel supports RLHF workflows programmatically via labeling functions and model-assisted labeling, with human review as needed.
HackerEarth's core products are developer assessments, hackathons, and coding challenges, not an RLHF data service — see the FAQ for scope.
How developer-native platforms generate coding data differently
Contractor-based vendors source labor into a labeling pipeline: recruit, train on a rubric, assign tasks, QA the output. Developer-native platforms invert that flow — they draw on existing engineer communities where code output, correctness signal (test-case pass rates), and solver identity are linked at the point of submission rather than reconstructed afterward through labeling. Toloka's expert tiers and Mercor's vetted engineer marketplace apply variants of the same idea, layering verified-engineer provenance onto what would otherwise be a generalist contractor pool.
Criteria for choosing the best alternatives to Scale AI for coding evaluation data
Four questions separate a serious shortlist from a vendor pitch deck:
- Who writes the code? Verified engineers, generalist annotators, or a mix. For nuanced evaluation, this is the top-line variable. For a deeper look at how to evaluate engineers directly, see Technical Skills Test for Hiring: Evaluate Developers.
- Where does the data come from? Original human submissions, labels on top of scraped code, or model-generated outputs with human review. Each has different IP and licensing implications.
- How is quality measured? Test-case pass rates, expert review, inter-rater agreement, or downstream model performance. Vendors that cannot answer this precisely are gambling with your eval set. For a framework on structuring quality signals in code evaluation, see HackerEarth's guide on 6 Things to Look for in a Coding Assessment Tool.
- What is the handoff? API, structured export, platform access, or a one-time delivery. ML teams that need continuous evaluation data should push on this early.
Frequently asked questions
Who is Scale AI's biggest competitor?
There isn't one. For general frontier-model data services, Surge AI and Labelbox are the most commonly named Scale-adjacent alternatives in buyer conversations. For coding evaluation specifically, procurement shortlists more often pair a contractor-based vendor (Surge, Appen, or Labelbox-managed) with a developer-native source (HackerEarth, Mercor, or Toloka's expert tiers) rather than picking a single replacement. If your legal team weights IP provenance heavily, the shortlist narrows toward vendors that can produce problem-authorship chains in writing.
What is the best AI evaluation data vendor?
There is no single best vendor; the right choice depends on the evaluation workload. For high-quality RLHF preference data, Surge AI is the most commonly cited Scale-adjacent choice. For engineer-authored problems with built-in correctness signal, developer-native platforms like HackerEarth fit better. For raw throughput and language coverage, Appen and Toloka lead. For teams that want to own the labeling workflow, Labelbox is the strongest platform play.
Is Scale AI still doing well after the Meta deal?
Scale remains operationally active and continues to serve enterprise customers, but Meta's $14.3 billion investment in June 2025 — which saw Alexandr Wang depart as CEO to serve as Meta's Chief AI Officer, co-leading Meta Superintelligence Labs with Nat Friedman, while remaining a Scale board director, with Scale naming Chief Strategy Officer Jason Droege as interim CEO — has prompted several large customers to reduce their dependence. The practical effect for buyers is more negotiating leverage and a stronger case for multi-vendor sourcing.
Can HackerEarth produce RLHF-style preference data on code?
HackerEarth's core products are developer assessments, hackathons, and coding challenges — not an RLHF data service. Teams interested in exploring whether its community-sourced code and ranking signals could support preference-data workflows should scope that directly with HackerEarth rather than treat it as an off-the-shelf capability.
How does pricing typically compare across these vendors?
Published pricing is rare across this category, and public comparisons are unreliable. Scale, Surge, Labelbox, and Snorkel typically require enterprise contracts; Appen and Toloka often operate on per-project or per-task terms. Expect six-figure annual commitments for serious frontier-model workloads regardless of vendor, and request itemized quotes rather than relying on third-party comparisons.
Is any of this data safe to use for commercial model training?
Only if the vendor can produce clear contributor contracts, problem-authorship chains, and IP assignment language. This is the single question most likely to kill a procurement in legal review. Vendors with community-sourced data and explicit terms of service covering submission rights generally have an easier audit trail than those relying on contractor networks with mixed documentation.
Key takeaways
- Scale AI's post-Meta positioning has made multi-vendor sourcing a baseline strategy for frontier-model teams in 2025.
- Developer-native platforms and contractor-based annotation shops produce structurally different data; the choice depends on whether verified-engineer provenance matters more than throughput.
- Surge AI remains the strongest Scale-adjacent choice for high-quality RLHF; Labelbox wins when you want to own the platform.
- Appen and Toloka are the volume plays; Snorkel is the programmatic play.
- Before signing, request contributor contracts, problem-authorship chains, and IP assignment language in writing — provenance gaps are the most common cause of failed legal review.
Next steps
If you are evaluating whether an engineer-authored problem library and community-generated coding submissions fit your evaluation-data needs, book a demo with HackerEarth about a scoped data partnership.
Disclosure: This article is published by HackerEarth. Vendor descriptions reflect public information current as of Q4 2025.




