Index.dev vs Mercor: full comparison for 2026
Quick verdict
Index.dev (4.5/5) edges ahead of Mercor (3.6/5) overall. Index.dev is the better choice for startups that want their money back if the first month doesn't work. Mercor is the stronger option for AI labs buying short-term expert work in volume. The right choice depends on your project size, budget, and required tech stack.
Index.dev vs Mercor: head-to-head summary
| Criterion | Index.dev | Mercor |
|---|---|---|
| Founded | 2019 | 2023 |
| HQ | London, United Kingdom | San Francisco, California, USA |
| Team size | 30,000+ network | 300–400 staff; large contractor network |
| Rating | 4.5 / 5 | 3.6 / 5 |
| Primary differentiator | A refundable 30-day trial on every placement, plus direct hire | Volume contractor hiring with a percentage platform fee |
| Pricing model | Monthly rate per engineer; direct-hire fee; 30-day refundable trial; rates on request | Contractor rate plus platform fee (about 30%, Sacra estimate) |
| Min. engagement | Not published | Not published |
| Primary tech stack | Python, PyTorch, LangChain | Python, PyTorch, OpenAI |
| Industries served | SaaS, Fintech, E-commerce, AI labs, Healthcare | AI labs, Technology, Finance, Legal, Healthcare |
Index.dev vs Mercor: overview
Index.dev
Index.dev, legally Index Soft Limited, is a London talent platform that its job ads date to 2019. Its buying terms are the clearest of any network here: every placement carries a 30-day trial with a full refund if the match fails. You can contract one engineer, build a dedicated offshore team or hire someone directly. The main pool of more than 30,000 engineers sits in Latin America and Central and Eastern Europe, and a separate AI unit supplies Master's and PhD-level people for fine-tuning and retrieval work. Vetting runs through five stages with human reviewers.
Mercor
Mercor was founded in San Francisco in 2023, employs roughly 300 to 400 people and screens applicants with AI interviews. It raised money at a $10 billion valuation in October 2025, mainly on the strength of supplying experts to AI labs. Its fee is the clearest thing to understand about buying from it: Sacra estimates it at about 30% on top of contractor pay. That model suits large, short-term expert work. For a year-long engineering seat, the fee adds up.
Services and capabilities: Index.dev vs Mercor
| Capability | Index.dev | Mercor |
|---|---|---|
| Full-time dedicated engineers | ✓ | ✗ |
| Part-time / fractional experts | ✗ | ✗ |
| Dedicated team | ✓ | ✗ |
| Trial before commitment | ✓ | ✗ |
| Published rates | ✗ | ✗ |
| Direct hire option | ✓ | ✗ |
| Subscription or output-based pricing | ✗ | ✗ |
| Nearshore time-zone overlap | ✓ | ✗ |
| LLM / GenAI engineers | ✓ | ✓ |
| MLOps | ✗ | ✗ |
| Computer vision | ✗ | ✗ |
| Data engineering | ✗ | ✗ |
Tech stack comparison: Index.dev vs Mercor
| Framework / platform | Index.dev | Mercor |
|---|---|---|
| PyTorch | ✓ | ✓ |
| TensorFlow | N/A | N/A |
| LangChain | ✓ | N/A |
| Hugging Face | ✓ | N/A |
| OpenAI | ✓ | ✓ |
| AWS | ✓ | ✓ |
| Azure | N/A | N/A |
| Google Cloud | ✓ | N/A |
| Databricks | N/A | N/A |
| Kubernetes | N/A | N/A |
Pricing comparison: Index.dev vs Mercor
| Criterion | Index.dev | Mercor |
|---|---|---|
| Minimum engagement | Not published | Not published |
| Engagement models | Full-time dedicated, Dedicated team, Direct hire, Trial period | Freelance contract |
| Rate transparency | Not public | Not public |
| Price tier | Mid-market | Mid-market |
Target audience comparison: Index.dev vs Mercor
| Dimension | Index.dev | Mercor |
|---|---|---|
| Best company size | Startup to mid-market | Startup to mid-market |
| Best industries | SaaS, Fintech, E-commerce | AI labs, Technology, Finance |
| Best use cases | Trialling a Latin American LLM engineer for a month, Hiring a PhD-level specialist to fine-tune a model | Hiring domain experts to evaluate a model, Adding a contract ML engineer for a research sprint |
| Typical project type | Full-time dedicated | Freelance contract |
Index.dev vs Mercor: pros and cons
| Index.dev | |
|---|---|
| + | A full refund in the first 30 days lowers the cost of a bad match |
| + | Contract and direct-hire routes from one provider |
| + | Talent in both U.S.-friendly and European time zones |
| - | Engineers are network members, not employees |
| - | Acceptance-rate figures are the company's own |
| - | No published monthly rates |
| Mercor | |
|---|---|
| + | Fast access to specialists |
| + | Simple percentage pricing |
| + | Well funded |
| - | About 30% fee on a long engagement |
| - | AI interviews, not engineers, do the first screen |
| - | Short track record with product teams |
Who should choose Index.dev?
A typical fit: trialling a Latin American LLM engineer for a month.
A refundable 30-day trial on every placement, plus direct hire. Minimum engagement is not publicly disclosed. Works best with clients in SaaS, Fintech, E-commerce, AI labs, Healthcare.
Who should choose Mercor?
A typical fit: hiring domain experts to evaluate a model.
Volume contractor hiring with a percentage platform fee. Minimum engagement is not publicly disclosed. Works best with clients in AI labs, Technology, Finance, Legal, Healthcare.
Decision matrix: Index.dev vs Mercor
| Your situation | Recommended choice |
|---|---|
| You want one engineer full-time on a monthly contract | Index.dev |
| You only need a specialist a few days a week | Neither advertises part-time experts; ask about reduced hours |
| You want to test an engineer before committing | Index.dev |
| You need a rate before the first call | Neither publishes rates; ask both for a written rate card |
| Your budget is at the lower end | Compare: Index.dev (Not published) vs Mercor (Not published) |
| You may want to hire the engineer permanently later | Index.dev |
| You want several engineers working as one team | Neither lists dedicated teams; check team size before signing |
Use case fit: Index.dev vs Mercor
| Use case | Index.dev fit | Mercor fit | Winner |
|---|---|---|---|
| Trialling a Latin American LLM engineer for a month | Strong | Limited | Index.dev |
| Hiring a PhD-level specialist to fine-tune a model | Strong | Strong | Both equally |
| Hiring domain experts to evaluate a model | Strong | Strong | Both equally |
| Adding a contract ML engineer for a research sprint | Limited | Strong | Mercor |
Verdict: Index.dev vs Mercor
Index.dev (4.5/5) is the stronger overall choice for most AI Staff Augmentation projects. A refundable 30-day trial on every placement, plus direct hire.
Mercor (3.6/5) is worth a look if you need adding a contract ML engineer for a research sprint. If your situation matches that, Mercor is a competitive option.
Related comparisons
Index.dev vs Mercor FAQ
Is Index.dev better than Mercor?
Index.dev (4.5/5) scores higher overall, but "better" depends on your use case. Index.dev's strongest advantage: a full refund in the first 30 days lowers the cost of a bad match. Mercor's strongest advantage: fast access to specialists.
How do Index.dev and Mercor differ in pricing?
Index.dev uses monthly rate per engineer; direct-hire fee; 30-day refundable trial; rates on request pricing. Mercor uses contractor rate plus platform fee (about 30%, sacra estimate) pricing. Neither firm publishes a full rate card; a discovery call is required for project-specific quotes.
Which is better for enterprise: Index.dev or Mercor?
Mercor is the larger team and typically the better enterprise-scale choice. For very large programmes, verify team size and compliance coverage directly with each provider before shortlisting.
What are the main differences between Index.dev and Mercor?
Index.dev's primary differentiator is: a refundable 30-day trial on every placement, plus direct hire. Mercor's primary differentiator is: volume contractor hiring with a percentage platform fee. They also differ in team size (30,000+ network vs 300–400 staff; large contractor network), minimum engagement (Not published vs Not published), and primary industries served (SaaS, Fintech vs AI labs, Technology).
Verify all details directly with each provider before making a decision.