AI Training Platforms Compared: Outlier vs. Appen vs. Aligner - Why the Newcomer Wins in 2025

In the booming world of artificial intelligence, the demand for high-quality data to train sophisticated models has created a surge in AI training platforms. These platforms offer freelancers and remote workers the opportunity to contribute to the development of cutting-edge AI while earning an income. Three of the most talked-about names in this space are Outlier, Appen, and the newcomer, Aligner.

But which platform is the right choice for you? In this detailed review, we’ll dive deep into the pros and cons of each, explore the recent changes that have impacted Outlier, and reveal why the new kid on the block, Aligner, might just be the best option for those looking to get into AI training.

Outlier: The Established Player Facing a Shake-Up

Outlier, a platform under the umbrella of Scale AI, has long been a go-to for many AI trainers. It’s known for its variety of tasks and has provided a steady stream of work for many. However, the landscape for Outlier has dramatically shifted following a major development: the acquisition of a 49% stake in its parent company, Scale AI, by Meta (formerly Facebook).

The Meta Effect: A Double-Edged Sword

This acquisition has had a significant and immediate impact on Outlier’s operations. On one hand, it signifies the platform’s importance in the AI industry. On the other, it has led to a noticeable reduction in work for many of its contractors.

Pros:

• Established Platform: Outlier has been around for a while and has a well-developed system for task distribution and payment.
• Variety of Projects: Historically, Outlier has offered a diverse range of projects, from data annotation to content evaluation.

Cons:

• Reduced Workload: Since the Meta acquisition, there have been widespread reports of a significant decrease in available projects. This is partly due to a large-scale layoff at Scale AI, which included both full-time employees and contractors.
• Uncertain Future: With some of Scale AI’s major clients, such as OpenAI, phasing out their work with the company, the future for Outlier’s contractors is uncertain.
• Increased Competition: The remaining projects on the platform are now being sought after by a larger pool of contractors, making it harder to secure consistent work.

Appen: The Veteran with a Mixed Reputation

Appen is another long-standing player in the AI training data industry. As a publicly traded company, it offers a sense of legitimacy that many other platforms lack. It has a massive global crowd of over a million contributors and works with some of the biggest tech companies in the world.

However, despite its impressive credentials, the experience of working with Appen can be a mixed bag.

Pros:

• Flexibility: Appen offers a high degree of flexibility, allowing you to work from anywhere, at any time.
• Accessibility: Many of Appen’s projects are beginner-friendly, with a low barrier to entry.
• Legitimacy: As a well-established company, you can be sure that Appen is a legitimate platform that pays its contributors.

Cons:

• Inconsistent and Low Pay: This is the most common complaint about Appen. Pay rates can be extremely low, sometimes falling far below minimum wage.
• Fluctuating Workload: Similar to Outlier, the availability of work on Appen can be unpredictable, making it an unreliable source of primary income.
• Poor Communication and Support: Many users report frustrating experiences with Appen’s support team, citing unhelpful responses and a lack of transparency.
• Platform Issues: The Appen platform itself can be clunky and prone to technical glitches.

Aligner: The Promising Newcomer

Aligner is the new player in the AI training space, and it’s already making waves. As a fresh platform, it’s not without its growing pains, but it’s also showing immense potential and is quickly becoming a favorite among many AI trainers.

A Fresh Start with a Focus on Quality

Aligner is positioning itself as a platform that values high-quality work and rewards its contributors accordingly. While it may not have the long track record of Outlier or Appen, it’s making up for it with its innovative approach and attractive pay rates.

Pros:

• Higher Pay: Many users are reporting significantly higher pay rates on Aligner compared to other platforms, with some projects offering the potential for a substantial income.
• Engaging Projects: Aligner seems to be focused on more complex and engaging tasks, which can be more rewarding for those with a keen eye for detail and a passion for AI.
• Growing Opportunities: As a new and rapidly growing platform, the number and variety of projects on Aligner are constantly increasing.
• Responsive and Evolving: Being a new platform, Aligner appears to be more agile and responsive to user feedback, with a team that is actively working to improve the user experience.

Cons:

• Inconsistent Work Availability: As a new platform, the workflow on Aligner can still be inconsistent at times. However, this is expected to improve as the platform grows.
• Communication Hurdles: Some users have reported issues with communication, which is a common challenge for fast-growing platforms.
• Growing Pains: As with any new venture, Aligner is still working out some of the kinks in its system. However, the platform’s commitment to improvement is a positive sign for the future.

The Verdict: Why Aligner Comes Out on Top

While Outlier and Appen have been the dominant players in the AI training space for years, the recent changes at Outlier and the long-standing issues with Appen have created an opening for a new and innovative platform to take the lead.

Aligner, with its focus on high-quality work, attractive pay rates, and commitment to improvement, is that platform. While it’s still in its early stages, the potential for growth and the positive experiences of many of its users make it the most exciting and promising option for AI trainers today.

If you’re looking to get into AI training or are looking for a better alternative to the established platforms, Aligner is the clear choice.

Ready to join the future of AI training? Sign up for Aligner today using the link below:

https://app.alignerr.com/signin?referral-code=0d310884-53bf-422f-a904-59c5b5dfb128