Content Gap Analysis: Finding What Your Competitors Rank For and You Don't

Editorial Team 2025-12-22 3 min read

Content Gaps Are Missed Opportunities With Data Behind Them

A content gap is a topic your competitors rank for and you don't. Simple concept, but the execution separates sites that grow organic traffic from those that plateau. It's not about copying competitors — it's about finding the topics your audience searches for that you haven't addressed yet.

The Ahrefs/Semrush Content Gap Method

Both tools have a dedicated content gap feature. In Ahrefs, it's called "Content Gap" under Site Explorer. In Semrush, it's the "Keyword Gap" tool. The process is identical:

  1. Enter your domain
  2. Enter 3-5 competitor domains
  3. Filter for keywords where at least 2 competitors rank in the top 20 but you don't rank at all
  4. Sort by search volume or traffic potential

This typically surfaces hundreds or thousands of keywords. The raw output is overwhelming, so filtering is essential.

Filtering the Noise

Not every gap is worth filling. Apply these filters:

  • Search volume floor — Set a minimum (50-100 monthly searches for most niches). Below that, the traffic payoff is too small.
  • Keyword difficulty ceiling — Unless your site has strong authority, filter out KD 70+ keywords. You'll need significant link building to compete there.
  • Relevance filter — Competitors often rank for terms outside your core focus. If you're a project management tool, you don't need to cover every "productivity" keyword Asana ranks for.
  • Intent alignment — Check that the keyword matches content you'd actually create. Transactional keywords for products you don't sell aren't gaps — they're someone else's business.

SERP Overlap Analysis

Content gap tools show keyword-level gaps. But SERP overlap analysis shows topic-level gaps, which is often more useful for content planning.

Here's the approach: for each competitor, export their top 50 organic pages by traffic. Map each page to a topic cluster. Compare clusters across competitors and your own site.

# Example topic cluster mapping
Competitor A top pages:
  /blog/git-branching-strategies   → Git workflows
  /blog/docker-compose-tutorial    → Docker
  /blog/kubernetes-networking      → Kubernetes
  /blog/ci-cd-pipeline-setup      → CI/CD

Your top pages:
  /blog/docker-getting-started     → Docker
  /blog/docker-multi-stage-builds  → Docker
  /blog/kubernetes-pods-explained  → Kubernetes

Gaps identified:
  - Git workflows (0 pages vs competitor's 4)
  - CI/CD (0 pages vs competitor's 6)

This reveals that you're missing entire topic clusters, not just individual keywords. That's a much more actionable insight for content strategy.

The People Also Ask Method

Here's a technique that doesn't require paid tools. For your core topics, search Google and expand every People Also Ask question. Each question reveals what searchers want to know that existing content might not fully answer.

Tools like AlsoAsked.com or the free PAA scraping in Python can scale this up. Export PAA questions for your top 50 target queries, deduplicate, and you'll have a solid list of questions your audience is asking.

Cross-reference these against your existing content. If your site covers "Docker networking" but doesn't address "how to connect Docker containers on different hosts" (a real PAA question), that's a content gap you can fill with a section or a standalone article.

Prioritizing Content Gaps

You'll end up with more gaps than you can fill. Prioritize using this framework:

High Priority

  • High search volume + low competition + directly relevant to your business
  • Topics where 3+ competitors rank but you have zero presence
  • Gaps in your existing topic clusters (you cover the cluster but miss important subtopics)

Medium Priority

  • Moderate search volume + moderate competition
  • Adjacent topics that your audience would find valuable
  • Gaps where you have some tangential content that could be expanded

Low Priority

  • Low volume keywords, even with low competition — the ceiling is too low
  • Topics only one competitor covers (might not be a real gap)
  • Queries outside your expertise or business focus

From Gaps to Content Calendar

Organize your gaps into a content calendar. Group related gaps into clusters and plan them as content series rather than disconnected one-offs. Five articles about CI/CD published over two months builds topical authority. Five articles about five unrelated topics doesn't.

For each gap, note:

  • Target keyword and search volume
  • Content format (based on SERP analysis)
  • Related internal pages to link from/to
  • Estimated effort (repurpose existing content vs. write from scratch)
  • Priority tier (high/medium/low)

Revisit your content gap analysis quarterly. New competitors enter the space, existing competitors publish new content, and search demand shifts. A gap that didn't exist three months ago might be your biggest opportunity today.