What Is Altern (altern.ai)?

Altern is an AI tool and agent directory: it indexes AI products into browsable categories, curated lists, alternatives, and a leaderboard, so you can find tools by task or industry instead of searching product by product. It's most useful when you already know the job you want done ("transcription," "lead generation," "contract management") and want a shortlist to compare. According to its homepage, it currently indexes 2,173 AIs.

What Altern actually offers

The site is organized around discovery rather than being a single AI product itself. Its own navigation and headings point to these sections:

• Categories — browse AI tools grouped by use case or industry.
• Lists — curated collections of tools around a theme.
• Alternatives — find substitutes for a tool you already know.
• Leaderboard — a ranked view of tools.
• Buildboard — a section tied to building or launching, shown with a weekly marker ("Buildboard · Week 4").
• Tasks — a way to start from a job to be done rather than a product name.

The homepage also shows a search-style prompt ("2173 AIs indexed ↑↓ navigate ↵ open"), suggesting you can navigate the index directly rather than only clicking through categories.

How broad is the coverage?

The category list is the clearest signal of scope. It runs from general business functions to narrow verticals. A sample of what's listed:

That spread matters: it means Altern is designed as a map of the AI product landscape, not a review site for a handful of tools.

When Altern is worth using

Use it when you want to:

• Start a tool search from a task — e.g., you need a transcription tool or a chatbot builder and want options grouped together.
• Do selection research — compare tools inside one category before committing time to trials.
• Find a replacement — the Alternatives section is built for swapping out a tool you're unhappy with.
• Scan the ecosystem — the leaderboard and curated lists give a quick read on what's popular or notable.

It's less suited to deep evaluation on its own. Altern is a directory, so expect it to point you toward tools and categories; hands-on testing, pricing checks, and feature verification still happen on each tool's own site.

Practical notes before you dive in

• Sign-in exists. The homepage includes a "Sign in to continue" prompt, so some actions may require an account. The available material doesn't specify which features are gated, so treat login requirements as something to check as you go.
• Pricing isn't stated for Altern itself. The page evidence contains no pricing signals, so don't assume the directory is free or paid based on this description alone.
• The index changes. The "2,173 AIs indexed" figure and the "Week 4" Buildboard marker indicate the catalog is actively updated, so counts and rankings will shift over time.

If your goal is to find AI tools for a specific job, the fastest path is to enter through Categories or Tasks, narrow to your use case, then use Alternatives and the Leaderboard to compare the shortlist.