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Overview
Moz pioneered many of the metrics SEOs use every day, including Domain Authority. Moz Pro bundles link research, keyword research, rank tracking and site audits with a strong focus on clarity and education.
Ahrefs started as a backlink tool and is known for one of the largest commercial link indexes. It has grown into a full SEO suite with keyword research, content research, rank tracking and site audits.
Both are excellent. The right choice depends on what you do most often.
Feature comparison
| Feature | Moz | Ahrefs |
|---|---|---|
| Authority metric | Domain Authority (DA), Page Authority (PA), Spam Score | Domain Rating (DR), URL Rating (UR) |
| Backlink research | Link Explorer — solid index, spam analysis | Site Explorer — very large, frequently refreshed index |
| Keyword research | Keyword Explorer with priority and difficulty scores | Keywords Explorer with large database and click data |
| Site audit | Site Crawl with clear explanations | Site Audit with detailed technical reports |
| Rank tracking | Included | Included |
| Local SEO | Moz Local (separate product) | Limited |
| API | Moz API (free tier available) | Enterprise API; free DR endpoint |
| Learning curve | Beginner-friendly, great documentation | Powerful, slightly steeper |
Plans and pricing change often — check each vendor's website for current details.
Link data and authority metrics
For pure backlink research, Ahrefs is widely regarded as the leader thanks to the size and freshness of its index. Moz's strength is in its metrics: DA is the most widely quoted authority score in the industry, and Spam Score is a useful extra filter when vetting link partners.
Many SEOs use both: Moz metrics for quick bulk vetting (DA, PA, Spam Score) and Ahrefs for deep dives into individual backlink profiles.
Who each tool is best for
Choose Moz if…
- You are newer to SEO and value clear explanations
- Clients and partners ask for Domain Authority
- You need local SEO tools
- You want an API with a free tier
Choose Ahrefs if…
- Backlink research is the core of your work
- You need the largest possible link index
- You do a lot of content and competitor research
- You prefer deep data over simplicity
Free alternatives
You don't need a paid plan to get started. Our Bulk DA PA Checker gives you Moz DA, PA and Spam Score for up to 20 sites at once, and our Backlink Checker and Website Authority Checker show link counts and authority grades — all free.
Frequently asked questions
Is Moz or Ahrefs better for beginners?
Moz is generally easier to learn thanks to its clear interface and extensive educational content. Ahrefs is very usable too, but it packs in more data.
Which has the bigger backlink index?
Ahrefs is widely considered to have one of the largest and most frequently refreshed commercial link indexes.
Can I use DA and DR together?
Yes — many SEOs check both. Just never compare one site's DA with another site's DR.
Are there free versions?
Both offer limited free tools. For free bulk Domain Authority checks, use our Bulk DA PA Checker.