Comparison · 4-min read
Flatline SEO vs SEOptimer
SEOptimer ships volume: 60+ free tools, 500+ blog posts, generic global focus. Flatline ships clarity: one excellent audit, plain-English findings, UK local-SEO built into the score. Both are 30-second audits — we think one finishes the job better.
Run a free audit£29
Flatline entry
vs $29 SEOptimer
Depth
Flatline focus
vs Breadth (60+ tools)
UK
Built for
vs Generic global
0-100
Score format
vs A-F letter
| Feature | Flatline SEO | SEOptimer |
|---|---|---|
| Free audit | ✓ Unlimited | ✓ Unlimited |
| Entry paid price | £29 / month | $29 / month (~£23) |
| Audit speed | ~15 seconds | ~30 seconds |
| Score format | Visibility 0-100 | Letter grade A-F + 0-100 |
| Findings prioritisation | Severity-grouped, plain-English explanations | High/Med/Low, technical labels |
| Audit category sections | 7 grouped sections | Mixed list, harder to scan |
| UK / GDPR data residency | ✓ EU-west-2 (London) | US/global hosting |
| Local-SEO weighting | ✓ Built into score | Add-on (paid plan) |
| Shareable public report | ✓ All tiers | ✓ Free-tier limited |
| Branded client reports | ✓ Pro tier (£79) | DIY $29 / White-label $39 |
| White-label + team seats | Agency £199 | Custom enterprise |
| 60+ specialist mini-tools | One excellent tool | ✓ Yes |
"SEOptimer's library of free tools is impressive but I never opened most of them. Flatline gave me one report I actually read end-to-end."
UK agency owner, comparing tools April 2026
Why pick Flatline
UK-built. Belfast-supported. Faster, with categorised findings you can fix without a glossary tab open. The audit reads like a senior SEO sat down with you, not a checklist printout. Severity badges tell you what to fix first, not just what's broken.
Why pick SEOptimer
If you actually need the suite of 60+ ancillary tools (meta tag generator, robots.txt builder, etc.) bundled in one subscription, SEOptimer's breadth is hard to match. We focus on doing one thing extraordinarily well.
Common questions
How does Flatline compare on price?+
Roughly equivalent at entry: £29 vs ~£23 (USD $29). For UK customers there's no FX hassle, no surprise VAT inclusions on the receipt, no chasing up subscription emails in dollars.
Does Flatline have white-label?+
Yes, Agency plan (£199/mo). SEOptimer's white-label tier starts at $39/mo but it's white-labelled tooling, not white-labelled audits. Both work; ours is bundled into one tier with team seats.
Can I run both audits and compare?+
Highly recommended. Both are free at the audit level. Run yours through each, decide which findings you'd actually act on. That's the right tool for you.
Does Flatline have a Chrome extension?+
Not yet — on the roadmap for Q3 2026. SEOptimer's extension is mature if that workflow matters to you.
Run both audits. Pick the report you'd actually act on
Both tools are free. Run your site through each. The one whose findings you understand and would actually implement, that's the right choice.