Comparison
Semrush alternative: OpenSEO vs Semrush
Semrush is a closed marketing suite on a monthly plan. OpenSEO is open source: you run it, own it, and pay only for the data you look up. Here is how they differ, and when Semrush is the better buy.
Starting price
Semrush pricing vs OpenSEO
Semrush Pro: $139.95 a month.
- 1 user
- Guru $249.95 and Business $499.95 a month
- Some toolkits sold separately
List prices on monthly billing, checked in October 2026. Semrush sets its own prices and changes them; check its pricing page for current figures. OpenSEO's data costs are at the time of writing; see Pricing.
OpenSEO vs Semrush: feature comparison
| Semrush | OpenSEO | |
|---|---|---|
| Source code | Closed | Open source (MIT), self-hostable |
| Price model | Monthly plan from $139.95 | Open-source software; data paid per lookup, from $0.01 |
| Scope | SEO plus ads, content, social and more | SEO: keywords, ranks, backlinks, audits, AI visibility, local |
| Keyword and backlink data | Own databases with long history | A large commercial dataset, through a data provider |
| Rank tracking | 500 tracked keywords on Pro | $0.10 per keyword and device for the top 100, on your schedule or on demand |
| AI agents | Check their current plans | 66 MCP tools and a REST API on every install, spending capped per call |
When to choose Semrush
- You run paid search, content and social from one place as well as SEO.
- You rely on years of historical data for trend analysis.
When to choose OpenSEO
- You want SEO only, without paying for the rest of a marketing suite.
- Your usage is uneven: some busy weeks, many quiet ones.
- You want an AI agent to work with your SEO data under a spending cap.
FAQ
OpenSEO vs Semrush FAQ
Is OpenSEO a free Semrush alternative?
The software is: OpenSEO is open source under the MIT licence and free to self-host, with no seats and no plan. Search data, like keyword volumes, rankings and backlinks, is paid per lookup at the price shown before it runs, so a quiet month costs little. The crawler, the site audit and your Search Console data cost nothing.
Is the data as good?
OpenSEO’s search data comes from YepAPI, a provider of a large commercial SEO dataset. It covers keyword volume, rankings, backlinks and SERPs well, but the big suites run their own crawlers and keyword databases, which are larger. For most site owners the difference matters less than the price; for agencies doing link research all day it can matter more.
What does OpenSEO actually cost?
The software is open source and free to self-host. Search data is paid per lookup, at the price shown before it runs: about $0.08 for a keyword search of 150 ideas, $0.10 for a rank check of the top 100. Tracking 100 keywords weekly on desktop costs about $43 a month.
Semrush is a trademark of its owner. OpenSEO is not affiliated with or endorsed by Semrush.