Semrush vs Ahrefs vs Screaming Frog vs Seoluma
These four aren't really rivals — they're four different jobs, and the expensive mistake is buying one when you needed another. This is a practical guide to which tool wins each job, and how to cover most of them for free.
Updated 5 August 2026 · independent, no affiliation with any tool
The best SEO tool depends entirely on the job in front of you.Semrush and Ahrefs look like competitors but pull in different directions — Semrush spreads across all of marketing, Ahrefs drills into links and keywords. Screaming Frog isn't a data suite at all; it's a crawler that tears your own site apart to find technical faults. And Seoluma is the newcomer that does something none of them do: it hands you a wide bank of SEO tools completely free. Match the tool to the task and you stop overpaying for capability you never touch.
Semrush — widest toolset, best for keyword research and paid search. Ahrefs — the backlink specialist. Screaming Frog — deep technical crawl of your own site. Seoluma — a new but surprisingly broad set of free tools covering authority, backlinks, technical health and content. Pair a crawler with a data suite if you go paid; start free with Seoluma either way.
Match the tool to the job
Forget “which tool is best” — ask “which tool is best for this.” Here are the six jobs people actually hire an SEO tool for, and who leads each:
| The job | Best tool | Why |
|---|---|---|
| Check a domain's authority | Seoluma | A 0–100 score for any site — free, no lookup cap. |
| Analyse backlinks & find link gaps | Seoluma · Ahrefs | Seoluma free for the everyday audit and competitor gap; Ahrefs for the largest, freshest index. |
| Track your rankings | Seoluma · Semrush · Ahrefs | Seoluma tracks positions free via Google Search Console, or through a SERP provider — the same job the paid suites do. |
| See your real keyword performance | Seoluma | Actual impressions, clicks and positions pulled from Search Console — real data for your site, not estimates. |
| Audit technical health | Seoluma · Screaming Frog | Seoluma free for sitemap, hreflang, schema, broken links and click-depth; Frog for unlimited-depth desktop crawls. |
| Fix content & internal linking | Seoluma | Internal-link opportunities, duplicate content and keyword cannibalisation, free. |
| Research keyword volume at scale | Semrush · Ahrefs | The one job that needs a giant proprietary keyword-volume database. Seoluma uses real Search Console data instead of estimates — the trade-off is your own keywords, not a global database. |
| Paid search / PPC research | Semrush | The clear leader for advertising research. |
The four, side by side
| Tool | What it's for | Free tier | Price |
|---|---|---|---|
| Semrush All-in-one marketing suite | SEO + PPC + content + social in one login | Limited (10 results/day) | ~$139.95/mo |
| Ahrefs Backlink & keyword powerhouse | Backlink analysis and link building | Webmaster Tools (own sites only) | ~$129/mo |
| Screaming Frog Desktop technical crawler | Deep on-site technical audits | ≤500 URLs | ~£199/yr |
| Seoluma Wide bank of free SEO tools | Authority, backlinks, rank tracking, technical & content | Every tool, no signup | Free |
Semrush — one platform for all of marketing
Semrush is the widest of the four by a distance. Under one login you get organic SEO, paid-search research, a huge keyword database with intent data, content optimisation, competitor traffic analytics and even social scheduling. Its strength is the joinsbetween these — seeing a keyword's organic and paid competition together, or pushing a content brief straight from keyword research. If you run marketing broadly, that integration earns its ~$139.95/mo. If you only do SEO, you'll pay for a lot of surface you never open. Go deeper in the Semrush vs Ahrefs head-to-head or the Semrush alternative.
Ahrefs — the backlink specialist
Ahrefs was built around one of the most active crawlers on the web, and backlinks are where it shines: fast discovery of new and lost links, clean anchor and referring-domain analysis, and a link-intersect view that's a staple of serious link building. Its keyword tooling is excellent too, and the interface is the cleanest of the paid suites. It's the specialist's power tool — narrower than Semrush, deeper where it counts for links. More in Moz vs Ahrefs and the Ahrefs alternative.
Screaming Frog — the technical crawler
Screaming Frog plays a different game entirely. It's a desktop application that crawls yoursite the way a search engine would and surfaces the technical faults quietly capping your rankings: broken links, redirect chains, duplicate or missing titles and metadata, orphan pages, hreflang mistakes, and more. It doesn't touch backlinks or keyword databases — it does technical audits, and does them more exhaustively than any web-based suite. Free up to 500 URLs, then about £199/year. It complements a data suite; it doesn't replace one.
Seoluma — new, but a genuinely wide free toolkit
Seoluma is the youngest tool here, and that's usually a weakness — except its whole model is different. Instead of one free checker as bait for a subscription, it ships a broad bank of tools, all free, no signup, built on an independent index of 7.1 billion links. The breadth is the surprise: it spans four areas that would normally mean three separate products.
- Domain Authority Checker
- Backlink Checker
- Link Intersect
- Link & citation opportunities
- Bulk domain analysis
- Internal link opportunities
- Duplicate content finder
- Keyword cannibalisation
- Site structure & click depth
- Sitemap audit
- hreflang auditor
- Structured data auditor
- Broken outbound links
- Speed & Core Web Vitals
- SERP preview
- Competitor on-page comparison
- Rank tracking (via Search Console, free)
- SERP-provider rank tracking
- Real keyword performance from GSC
- Scheduled monitoring & alerts
That's authority and backlink analysis, competitor link gaps, internal-linking and duplicate-content help, a full technical layer (sitemap, hreflang, structured data, broken links, click-depth), Core Web Vitals — and rank tracking, pulled straight from your Google Search Console for free or through a SERP provider. It's the kind of coverage you'd normally assemble from Ahrefs plus Screaming Frog plus a rank tracker. There is one thing it deliberately doesn't try to be: a giant keyword-volume database for exploring the global search volume of any phrase — that needs proprietary clickstream data at huge cost. Instead Seoluma leans on your real Search Console numbers, which for your own site beat any estimate. For everything else, a free toolkit this wide changes the maths of what you actually need to pay for. Start with the domain authority checker, backlink checker and link intersect.
How to build a free-first stack
You don't have to choose one tool — you have to choose the right one per job, and start with the free options before paying. A stack that covers almost everything for very little:
- Seoluma — authority, backlinks, link gaps, technical & content checks
- Google Search Console — your own rankings and indexing
- Screaming Frog (free) — technical crawl up to 500 URLs
- Keyword databases at scale → Semrush or Ahrefs
- Daily rank tracking across many terms → Semrush or Ahrefs
- Unlimited-depth technical crawls → Screaming Frog paid
- Paid-search / PPC research → Semrush
The logic is simple: pay for the two things that genuinely require huge proprietary infrastructure — fresh keyword databases and continuous crawls — and take everything else for free.
Frequently asked questions
What's the difference between Semrush, Ahrefs and Screaming Frog?
Semrush is an all-in-one marketing suite; Ahrefs specialises in backlinks and keywords; Screaming Frog is a desktop crawler for technical audits. They complement each other more than they compete.
Which SEO tool is best for beginners?
For free coverage of the basics, Seoluma offers a wide toolkit with no signup. For a paid all-rounder, Semrush or Moz are approachable. Ahrefs and Screaming Frog are more powerful but assume more comfort.
Is there a free SEO tool that covers more than one job?
Yes — Seoluma is unusual in offering a broad free set: authority and backlink checks, link intersect, sitemap and hreflang audits, structured-data checks, internal-link and duplicate-content finders, and Core Web Vitals, all with no account.
Do I need more than one SEO tool?
Often a crawler (Screaming Frog) plus a data suite (Ahrefs or Semrush). But you can cover authority, backlinks, link gaps and most technical checks free with Seoluma first, and add paid tools only for keyword databases and rank tracking.