SEO crawlers · Updated August 2026
Screaming Frog vs Sitebulb vs LibreCrawl Which SEO crawler fits the sites you audit in 2026?
A side-by-side look at Screaming Frog, Sitebulb and LibreCrawl, built only from what each tool publishes on its own site. Pricing, crawl limits and feature availability are quoted as documented — where a tool does not state something, we say so rather than guess.
Screaming Frog 
Sitebulb 
LibreCrawl The quick verdict
Three crawlers, three different jobs.
Every tool here fetches pages and reports on what it finds. What separates them is how much you pay per seat, how big a site each can finish, whether anyone else on your team can see the data, and whether you own the code.
Screaming Frog Industry standard
Screaming Frog is the desktop default: 300+ issue checks, the deepest configuration options here, and a free tier that crawls 500 URLs with no sign-up.
- Checks for over 300 SEO issues, warnings and opportunities
- Free tier crawls 500 URLs with no sign-up or email capture
- Custom extraction with XPath, CSS Path, regex and custom JavaScript
- Its site names Apple, Google, Disney, Amazon and NASA as users
Sitebulb Desktop and cloud
Sitebulb is the only one here that sells both a desktop app and a cloud crawler, and the only one that pre-prioritises its 300+ checks into ranked Hints.
- Hints rank every issue Critical, High, Medium or Low with an explanation
- Desktop and Cloud are the same tool, so you can move up without switching
- JavaScript crawling is included on every plan at no extra cost
- Audit comparison tracks every datapoint between two crawls
LibreCrawl Free and open source
LibreCrawl is a free MIT-licensed crawler you host yourself, with unlimited URLs, Playwright rendering and a documented REST API.
- Free with no paid tier at all, under an MIT licence
- Unlimited URLs, with 1M+ crawls documented as stable
- Self-hosted, so crawl data never leaves your infrastructure
- A documented REST API and a drop-in JavaScript plugin system
At a glance
The scoreboard
Highlighted cells mark the stronger option on that metric. No highlight means the values are not directly comparable, or it is a tie.
Feature matrix
The full comparison
Every row reflects what Screaming Frog, Sitebulb and LibreCrawl document on their own websites, checked on 16 August 2026. "Not stated" means the tool does not publish the detail — not that the feature is definitely missing.
| Feature |
Screaming Frog
|
Sitebulb
|
LibreCrawl
|
|---|---|---|---|
| Pricing & licensing | |||
| Free version | Partial. 500 URL crawl limit | Partial. 14-day trial only | Supported. Entire tool is free |
| Entry paid price | $279/yr (£199) | $180/yr Lite | No paid tier |
| What one licence covers | 1 user, per year | 1 user; extras from $115.60/yr | Unlimited users, self-hosted |
| Volume discount | Supported. Down to £169 at 20+ licences | Partial. 15% off yearly plans | Not available. Not applicable |
| Money-back or trial terms | Partial. Free version, no refund policy stated | Supported. 14 days free, no card, cancel anytime | Not applicable |
| Crawl credits | Supported. None | Supported. None — stated explicitly | Supported. None |
| Open source licence | Not available. Proprietary | Not available. Proprietary | Supported. MIT |
| Crawling & scale | |||
| Documented URL ceiling | Unlimited, bounded by hardware | 500k desktop, 10M cloud | Unlimited, 1M+ stable |
| JavaScript rendering | Supported. Chromium WRS, paid only | Supported. Evergreen Chromium, all plans | Supported. Playwright, headless or headed |
| Cloud crawling | Not available. Desktop only | Supported. Sitebulb Cloud | Partial. Self-host it anywhere |
| Runs without tying up your machine | Not available. Runs locally | Partial. Cloud plans only | Partial. If you host it elsewhere |
| Concurrent crawls | Not available. Not stated | Partial. Cloud MEDIUM and above | Supported. Multi-tenant sessions |
| Scheduled or recurring crawls | Supported. Scheduling + command line | Supported. Pro and Cloud | Not available. Not stated |
| Crawl configuration depth | Supported. Paid unlocks full configuration | Supported. Advanced configuration on Pro | Supported. Depth, delays, proxies, filters, robots |
| Custom user agent & headers | Supported. Any header, custom UA | Partial. Not detailed on site | Supported. User agent, timeouts, proxy |
| Forms-based authentication | Supported. Paid only | Not available. Not stated | Not available. Not stated |
| Analysis & reporting | |||
| Issue checks documented | 300+ | 300+ Hints on Pro, 100+ on Lite | Automated issue detection, count not stated |
| Issues pre-prioritised for you | Partial. Type and estimated priority per issue | Supported. Critical/High/Medium/Low Hints | Partial. Issue detection and filtering |
| Crawl comparison over time | Supported. Crawl comparison + URL mapping | Supported. Audit comparison + trendlines | Not available. Not stated |
| Staging vs production comparison | Supported. Advanced URL mapping | Not available. Not stated | Not available. Not stated |
| PDF client reports | Not available. Not stated | Supported. Customised PDF reports on Pro | Not available. Not stated |
| Site architecture visualisations | Supported. Force-directed and tree graphs | Supported. Crawl maps, charts, timelines | Partial. Graph visualisation endpoint |
| Structured data validation | Supported. Schema.org + Google rich results | Supported. Structured data validator | Supported. Schema markup validation |
| Accessibility auditing | Supported. AXE ruleset, WCAG | Supported. Accessibility report | Not available. Not stated |
| Duplicate & near-duplicate content | Supported. md5, near-duplicate, vector embeddings | Supported. Duplicate content report | Supported. Duplicate content detection |
| Spelling & grammar checks | Supported. 25+ languages | Partial. Spell checker, Pro only | Not available. Not stated |
| Log file analysis | Partial. Separate product, £99/yr | Not available. Not stated | Not available. Not stated |
| Markdown extraction for LLMs | Partial. Documented via custom extraction | Not available. Not stated | Not available. Not stated |
| Export formats | Spreadsheet export, Google Sheets | CSV, PDF, Google Sheets | CSV, JSON, XML, custom fields |
| Integrations & automation | |||
| Google Search Console | Supported. Search Analytics + URL Inspection | Supported. Search Traffic report | Not available. Not stated |
| Google Analytics | Supported. User and conversion data in-crawl | Supported. GA4 engagement data | Not available. Not stated |
| PageSpeed Insights | Supported. Lighthouse + CrUX at scale | Supported. Performance report via Chromium | Supported. PSI integration, own API key |
| Looker Studio / Data Studio | Supported. Looker Studio crawl report | Supported. Live connector on Cloud | Not available. Not stated |
| Third-party link metrics | Supported. Majestic, Ahrefs, Moz | Not available. Not stated | Not available. Not stated |
| AI model integration | Supported. OpenAI, Gemini, Ollama, Anthropic | Partial. MCP listed as coming soon | Not available. Not stated |
| Public API | Partial. Command line automation, no API | Not available. Not stated | Supported. 19 documented REST endpoints |
| Extensible with your own code | Partial. Custom JavaScript during a crawl | Not available. Not stated | Supported. Drop-in JS plugin system |
| Platform & team | |||
| Runs on | Windows, macOS, Linux | Windows, macOS, or browser | Browser, self-hosted |
| Team collaboration on one crawl | Not available. Single desktop instance | Supported. Shared workspace on Cloud | Partial. Isolated sessions per user |
| Data stays on your infrastructure | Supported. Desktop, local storage | Partial. Desktop yes, Cloud is vendor-hosted | Supported. Self-hosted |
| Vendor support | Supported. Free technical support, free and paid | Supported. Support from the team that built it | Not available. Community, via GitHub |
| Training & education material | Supported. User guide, tutorials, paid training | Supported. Masterclasses, Hint explanations, guides | Partial. README and API docs |
| Product maturity | SEO Spider v24, released May 2026 | Launched 2017 | 100 commits, MIT, active |
Pricing
What a year of crawling costs
Entry pricing reads as Screaming Frog at $279/yr, Sitebulb at $180/yr, LibreCrawl at $0.
Screaming Frog and Sitebulb charge per user per year, so a five-person team pays five times. Screaming Frog discounts to £169 per licence at 20 or more. Sitebulb adds users to a Pro plan from $115.60 a year each, and takes 15% off yearly billing. LibreCrawl charges nothing at all — the cost is the server you run it on and the time you spend maintaining it.
Edge: LibreCrawl on price
Scale
How big a site each one can finish
On documented ceilings: Screaming Frog unlimited*, Sitebulb 500,000, LibreCrawl unlimited.
Screaming Frog's paid limit is unlimited in principle but bounded by the memory and disk on your machine; it uses a hybrid storage engine that writes to disk for large crawls. Sitebulb sets a 500,000 URL default on Pro, raisable to 2 million with a warning about your hardware, and moves to 10 million per audit on Cloud where the crawl runs on its servers. LibreCrawl documents 1M+ URL crawls as stable, using real-time memory profiling and virtual scrolling, and its crawler depth setting goes to 5 million.
No clear edge: the ceilings are stated differently
Control
Who owns the tool and where the data sits
LibreCrawl is open source and self-hosted, so the crawl data never leaves infrastructure you control and you can read or change the code.
Screaming Frog and Sitebulb are proprietary. Screaming Frog runs entirely on your desktop, so the data stays local even though the code is closed. Sitebulb Desktop is the same — local data, closed code — while Sitebulb Cloud stores your audits on its servers in exchange for team access and crawls that run without your machine. The trade with LibreCrawl is support: neither offers a vendor support channel, so problems go to GitHub rather than a helpdesk.
Edge: LibreCrawl on ownership
Pricing
What each plan actually costs
List prices as published by each tool. Screaming Frog and Sitebulb both quote in several currencies; the USD figures below come from their own currency switchers.
Screaming Frog - 500 URL crawl limit
- No sign-up or email capture
- No saving crawls, JavaScript rendering, custom extraction or API integrations
- £199/yr in GBP, per licence per user
- Unlimited crawl limit, bounded by memory and storage
- Full configuration, scheduling and all integrations
- Licence lasts 1 year, then renews
- £189 per licence per year
- £179 per licence per year
- £169 per licence per year
- Sold separately from the SEO Spider
- Free to 1,000 log events and 1 project
Sitebulb - 14 days, equivalent to Pro
- No credit card required
- 1 user, $18/month billed monthly
- 10,000 URLs per audit
- 100+ Hints, JavaScript crawling, GA/GSC/Sheets, crawl maps
- 1 user, $42/month billed monthly
- 500,000 URLs per audit, raisable to 2 million
- 300+ Hints, advanced configuration, audit comparisons
- Scheduled audits and customised PDF reports
- Extra users from $115.60/yr
- $125/month, 2 users
- 50,000 URLs per month, 50,000 per audit
- Unlimited projects, recurring audits
- 5 users, includes desktop licences
- 1 million URLs per month, 250,000 per audit
- 10 users, includes desktop licences
- 2.5 million URLs per month, 1 million per audit
- Concurrent crawling
LibreCrawl - MIT licence, full source on GitHub
- Unlimited URLs and unlimited exports
- Self-hosted via Docker or Python 3.8+
- No paid tier and no paywalled features
- Guest: 3 crawls per 24 hours, IP-tracked
- User: unlimited crawls, settings and export
- Extra: JavaScript rendering, custom filters, custom CSS
- Admin: concurrency, memory limits, proxy configuration
- Every user gets admin tier
- No rate limits or tier restrictions
Prices verified 16 August 2026. See vendor sites for current pricing.
Decision guide
Who should choose which
Choose Screaming Frog if…
- You want the tool most SEO documentation and tutorials assume
- Custom extraction and custom JavaScript during a crawl are part of your workflow
- You need AI prompts against crawled pages via OpenAI, Gemini, Ollama or Anthropic
- Link metrics from Majestic, Ahrefs or Moz should flow into the crawl
Choose Sitebulb if…
- You report to clients and want copy-pasteable issue explanations and PDF reports
- You want prioritisation done for you rather than sorting a spreadsheet
- Your team needs to work from the same crawl data at the same time
- You expect to outgrow a desktop machine and want a cloud path that is not a re-platform
Choose LibreCrawl if…
- Tool budget is the constraint and you can run Docker or Python
- Data governance means crawl data has to stay on your own servers
- You want to script against a crawler or extend it with your own tabs
- Several people need to crawl at once from one shared install
LibreCrawl costs nothing, but asks you to host and maintain it. Screaming Frog and Sitebulb charge per seat per year and hand you support, reporting and integrations in return. The deciding question is not the price — it is what you are auditing, and who keeps the tool running when a crawl fails.
From the AngleOut team
The crawler is the easy part
A crawler hands you a list of issues. It will not tell you which of them are costing you rankings, or what to fix first given your traffic. If you want that turned into a prioritised plan, we can put one together.
FAQ
Frequently asked questions
Which of Screaming Frog, Sitebulb and LibreCrawl is free?
LibreCrawl is entirely free under an MIT licence, with no paid tier. Screaming Frog ships a free version that crawls 500 URLs with no sign-up, but holds back saving crawls, JavaScript rendering, custom extraction and the API integrations for paid licences. Sitebulb has no free tier — it offers a 14-day Pro-equivalent trial with no credit card, after which Lite starts at $180 a year.
Which one handles the biggest sites?
Screaming Frog unlimited*, Sitebulb 500,000, LibreCrawl unlimited. Sitebulb Cloud is the only one here that crawls at scale on someone else's servers, up to 10 million URLs per audit. The unlimited figures are honest but conditional: both are bounded in practice by the memory and disk of the machine doing the crawling.
Do they all render JavaScript?
Screaming Frog renders with an integrated Chromium WRS, but only on a paid licence. Sitebulb uses an Evergreen Chromium engine and includes rendering on every plan at no extra cost. LibreCrawl uses Playwright and supports both headless and headed modes.
Can a team share one crawl?
Sitebulb Cloud puts audits in a shared workspace, so anyone on the team can open the same crawl with the same settings. Screaming Frog is a single desktop instance per licence, and licences are per user, so sharing means exporting. LibreCrawl supports several concurrent users on one install, but each session is isolated with its own crawler and data.
Which integrates with Google Search Console and Analytics?
Screaming Frog connects to the Search Analytics and URL Inspection APIs plus Google Analytics and PageSpeed Insights, and pulls link metrics from Majestic, Ahrefs and Moz. Sitebulb connects Search Console, GA4, Google Sheets and Data Studio, and lists an MCP integration as coming soon. LibreCrawl integrates PageSpeed Insights with your own Google API key, but documents no Search Console or Analytics connection.
What happens when something breaks?
Screaming Frog offers free technical support on both the free and paid versions. Sitebulb says support comes from the team that built the tool, rather than account management. LibreCrawl has no vendor support channel — you raise issues on GitHub and wait for a maintainer, or fix it yourself.