TEARDOWN 75 · REVIEWED 2026-08-18
Oncrawl
Oncrawl is a technical SEO platform that combines crawling the site you point it at with analysis of your own server log files, cross-referencing the two to show how Googlebot, Bingbot, and AI crawlers actually behave on your pages — not just how a simulated crawl thinks they should. It's cloud-hosted and sold entirely through a sales conversation, with no published pricing tiers.
Site crawling is a known weekend build; matching Oncrawl's pipeline that parses and cross-references hundreds of millions of real server-log lines a day against crawl data, without sampling, is a genuine data-engineering project most teams won't build for one site.
What you lose building it yourself
- ✕Cross-referencing real bot behavior (Googlebot, Bingbot, AI crawlers) from your own server logs against crawl data
- ✕Processing hundreds of millions of log lines a day without building that pipeline yourself
- ✕Pre-built segmentation and reporting that ties crawl, log, and ranking data together
Why people still pay
The join itself is simple; keeping it accurate and fast at real traffic volumes — reliably classifying bot traffic as user agents change, handling log files too large to fit in memory, and doing it continuously rather than as a one-off script — is the part that turns into ongoing engineering work most teams would rather not own.
BUILD YOUR OWN · WEEKEND CRAWL, HARDER LOG PIPELINE
A basic site crawler is a realistic weekend build for an AI coding tool, same as any other technical SEO crawler. Cross-referencing that with your own server logs at real scale — parsing large log files, reliably identifying bot traffic, and joining it against crawl data without silently dropping rows — is a genuine data-engineering project, closer to a multi-week build than a weekend one.
StackPlaywright or Puppeteer for the site crawl · a log parser (a Python script classifying bot user-agents from raw access logs) · SQLite to join crawl and log data by URL.
Build two Python scripts. First, a crawler using Playwright that follows same-domain internal links up to 500 pages, recording URL, status code, and title to a SQLite table. Second, a log parser that reads a standard Apache/Nginx access log file, extracts each request's URL, user-agent, and timestamp, and classifies known bot user-agents (Googlebot, Bingbot, GPTBot) into a second SQLite table. Join the two tables on URL and output a CSV showing, per page: whether it was crawled, whether any known bot hit it in the log file, and how many times. Cap the log file read at 1GB for this pass.
Similar tools
Free alternative: LibreCrawl — covers the free crawl side of the job with no URL cap; nothing free replicates Oncrawl's log-file analysis pipeline, which cross-references real bot behavior against crawl data — that's the part actually being paid for
Vendor's own claim
"Oncrawl collects, cross-references, and analyzes massive volumes of crawl, log, and performance data with zero sampling, giving your team a reliable foundation for every technical SEO decision, across traditional and AI search."
oncrawl.com · RETRIEVED 2026-08-18
QUESTIONS
Does Oncrawl publish pricing?
No — as of August 2026 its pricing page redirects to the homepage, and plans are quoted after a demo. Some third-party trackers list older self-serve tiers, but Oncrawl's current site shows no public pricing.
What does 'log file analysis' actually mean here?
Oncrawl ingests your website's own server access logs — the record of every request your server received — and matches each entry against its crawl data to show which pages real search-engine and AI bots actually visited, not just which pages a simulated crawl found.
Do I need my own server logs to use Oncrawl?
Yes, for the log-analysis half of the product — you or your hosting provider have to export and upload raw server logs. The crawl half works without them, but log analysis is the feature that differentiates Oncrawl from a standard site crawler.