# How to Vibe Code Your Own Oncrawl (and Stop Paying for It)

> Technical SEO Data for Competitive Websites

- Site: https://oncrawl.com
- Category: SEO & Analytics SaaS
- Platforms: Web app
- Verdict: **Serious undertaking** (38/100 vibecodeable)
- Estimated effort: 3-4 months of part-time engineering

## Verdict

Build a simplified single-project URL checker and log viewer instead of paying thousands, but keep paying for Oncrawl if you need massive enterprise log scale.

Oncrawl is an enterprise data powerhouse built on distributed log pipelines, heavy headless browser clusters, and complex graph analytics. While a solo developer can build a personal mini-crawler with Playwright and SQLite, scaling it to handle millions of JavaScript-rendered pages and raw log ingestion without crashing requires serious systems engineering. The AI and log correlation layers will demand weeks of careful background worker tuning.

### What you can't replicate

- Enterprise data infrastructure capable of processing 500M daily log lines
- The exact historical data retention across 1,000+ enterprise clients
- Advanced distributed IP rotation and anti-bot evasion networks

## What it does

Enterprise technical SEO and data platform combining crawl data, log analysis, and AI search lenses.

### Core features

- Headless browser JS site crawler handling large page counts
- Server log file ingestion and bot hit correlation
- Structural link-graph analyzer and orphan page detector
- Google Search Console API integration
- AI Search Lens for tracking LLM bot traffic and citations
- Content Lens for scoring SEO readiness
- REST API data export and custom segmentation matrices

## The business

### Pricing

- Starter / Small Setup: $69/mo — Designed for smaller setups and starting technical audits.
- Enterprise / Agency: $1,900+/mo — Full enterprise suite with advanced log parsing, JS rendering, and AI Search Lenses.

### Funding

$4.76M raised.
- Series A
Investors: Aquiti Gestion, IRDI Soridec Gestion (IRDI-ICSO)

Founded 2013.
Team size: 41-53.

## The hard parts

- Orchestrating distributed headless browser scrapers at scale without getting blocked or running out of memory
- Parsing and storing hundreds of millions of raw unstructured log lines efficiently
- Building a high-performance relational graph engine to compute internal link structures and crawl depth instantly
- Correlating asynchronous log timestamps with periodic crawl snapshots and external GSC ranking data

## How to vibe code Oncrawl

### Prerequisites

- Node.js (free): Runtime for building the Next.js app and scraper workers
- GitHub (free): Code repository and CI/CD triggers
- Supabase Account (free): Provides Postgres and vector storage for crawl results and logs

### Recommended AI tools

- Claude Code: Best-in-class agentic coding tool for scaffolding complex multi-file crawler services and parsers
- Cursor: Ideal for iterative UI work on the dashboards and segmentation matrices

### Stack

- Frontend: Next.js
- Backend: Node.js / Express worker pool
- Database: Supabase
- Auth: better-auth
- Payments: none
- Other: Playwright, Vercel AI SDK, Tailwind CSS, shadcn/ui

### Hosting

- Railway (Runs long-lived background crawler workers and log ingestion queues): $10/mo
- Vercel (Hosts the Next.js dashboard frontend and API routes): $0/mo

### Build guide

1. **Project Scaffolding & Database Schema** — Initialize the Next.js 16 app with Tailwind CSS, shadcn/ui, and configure Supabase Postgres tables for projects, URLs, crawl sessions, and raw log records.

```
Initialize a Next.js 16 project with TypeScript, Tailwind CSS, and shadcn/ui components. Configure better-auth for single-user authentication. Set up Supabase client connections and create SQL migrations for relational tables: `projects` (id, name, target_url), `crawls` (id, project_id, status, started_at, finished_at), `urls` (id, crawl_id, url, status_code, depth, title, load_time, content_type), and `server_logs` (id, project_id, ip, timestamp, method, path, user_agent, status_code). Ensure full type safety across all database queries.
```

2. **Headless Crawler Worker Engine** — Build a recursive web crawler using Playwright that respects robots.txt, renders JavaScript, extracts internal links, and streams results back to the database.

```
Build a robust Node.js crawler worker script using Playwright and Cheerio. The worker should take a `crawl_id` and `target_url`, fetch `robots.txt`, parse sitemaps if available, and recursively visit internal links up to a configurable depth limit. For each page visited, capture the HTTP status code, page load time, title, meta description, and extract all outgoing anchor links. Handle timeouts, redirects, and JS rendering errors gracefully. Stream the parsed URL data in batches back to Supabase to prevent out-of-memory errors on large crawls.
```

3. **Server Log Ingestion & Bot Hit Analyzer** — Implement a log parser endpoint that ingests standard Apache/Nginx log formats or custom JSON logs, parsing bot signatures to distinguish Googlebot, Bingbot, and AI crawlers.

```
Create a backend log ingestion service and API route in Next.js that accepts raw server log uploads (CSV or text files). Write a robust regex parser that extracts IP addresses, timestamps, HTTP methods, request paths, status codes, and User-Agents from each log line. Automatically classify User-Agents into categories (Googlebot, Bingbot, AI Bots like ChatGPT-User/ClaudeBot, and Standard Users). Store parsed logs in the `server_logs` table, indexed by path and timestamp for fast cross-referencing against crawl results.
```

4. **Link Graph & Architecture Analysis Module** — Develop analytical queries and visual components to calculate internal link distribution, spot orphan pages, and detect structural bottlenecks.

```
Build an analytics calculation engine and UI dashboard for site architecture. Write SQL/TypeScript logic to analyze the `urls` table and compute: internal link count per page, distribution of crawl depth, identification of orphan pages (pages with 0 incoming internal links), and broken internal links (404/5xx status codes). Present these findings in a clean dashboard using shadcn/ui data tables and Recharts charts, allowing users to filter by depth and status code.
```

5. **AI Search Lens & Content Evaluation** — Integrate the Vercel AI SDK and OpenAI API to analyze scraped page content quality and track AI bot activity patterns from ingested logs.

```
Implement an 'AI Search Lens' and 'Content Lens' feature using the Vercel AI SDK and OpenAI API. Create a background job that samples page content from completed crawls, sends it to the LLM to grade SEO readiness, readability, and content depth (returning a structured score and actionable recommendations). Also, build a log aggregation view specifically isolating AI bot hits (ChatGPT-User, ClaudeBot, PerplexityBot) against site pages to show which sections of the site receive the most AI crawler attention.
```

6. **Export API & Final Polish** — Add a full REST API for data export and polish the overall workflow with status indicators, notifications, and error boundary handling.

```
Build a secure REST API protected by bearer tokens that lets users trigger new crawls, check crawl status, and export crawl data and log analysis summaries as JSON or CSV. Add comprehensive error handling, toast notifications for worker actions, and clean up the UI layout to match a professional enterprise SEO dashboard aesthetic.
```

### Cost vs paying

**Starting costs (one-time):**

- Domain name (optional): $12
- Total: ~$12 one-time

**Ongoing costs (monthly):**

- Railway background worker hosting: $10/mo
- OpenAI API credits for Content Lens evaluation: $5/mo
- Total: ~$15/mo

- Paying for the SaaS instead: $69/mo to $1,900+/mo
- Build time: 40-60 hours
- AI tool credits: $20 (Claude Pro)
- Break-even: Instant (for personal dev tools)

## Sources

- [Oncrawl Official Website](https://oncrawl.com)
- [GetLatka - Oncrawl Revenue & Metrics Profile](https://getlatka.com/companies/oncrawl)
- [PitchBook - Oncrawl Company Profile & Acquisition Data](https://pitchbook.com)
- [GrowthSupermarket - Oncrawl Pricing & Features Guide](https://growthsupermarket.com)