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Broken Link Pattern Checker
Broken link checker
Statically analyze href attributes and pasted URLs for javascript: pseudo-links, odd schemes, and other red flags - pair with real crawls for HTTP status.
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Quick answer: Broken Link Pattern Checker
Static scan for risky href schemes and malformed URLs before you pay for a full crawl.
Example: Paste landing HTML → flag `javascript:void(0)` CTA, OK relative `/pricing` paths, OK `mailto:` support links.
Calculations follow the documented formula on this page; rounding and input units can change the last digit—treat outputs as educational estimates unless you reconcile with source systems.
* This is an estimate. Actual amounts may vary slightly based on input assumptions.
What this calculator does
- Broken Link Pattern Checker
- Scan HTML for risky or malformed link hrefs before launch.
javascript: and odd protocols break accessibility and SEO flows; this flags obvious foot-guns, not remote 404s.
Statically analyze href attributes and pasted URLs for javascript: pseudo-links, odd schemes, and other red flags - pair with real crawls for HTTP status.
Inputs on this page: HTML (optional), Extra URLs (one per line, optional). Assumptions stay visible so you can reproduce the figure elsewhere.
When to use it
- Use Broken Link Pattern Checker when you need a transparent broken link checker answer before you commit numbers to a spreadsheet, invoice, or conversation.
- Reach for it when you already know (or can estimate) HTML (optional) and want the dependent result without rebuilding the formula by hand.
- Skip it when you need certified advice, signed-off payroll, or a lender’s official quote—those require the primary institution’s systems.
Key takeaways
- Trackers sometimes rewrite URLs - inspect final HTML, not just CMS preview.
- Empty hrefs are clickable traps - use buttons for actions instead.
- Pair with log-based 404 monitoring after launches.
How to use this tool
- 1Paste HTML containing links, or a list of absolute URLs, or both.
- 2Run the scan to flag suspicious schemes.
- 3Fix javascript: anchors into buttons where appropriate.
- 4Follow up with a crawler or log-based 404 monitor for live status codes.
Guides and explainers
Long-form walkthroughs that pair well with this calculator. When you need narrative context beyond the live fields, start here and return to the tool to plug in your own numbers.
JSON formatting and validation explained for developers (2026)
Cover JSON syntax footguns, minify vs pretty-print trade-offs, formatter vs validator vs schema roles, and link to Toollabz JSON formatter/validator, URL encoding, regex guide, and developer hub.
Read guide →Regex beginner guide: practical patterns (without catastrophic backtracking) (2026)
Teach literals, anchors, three copy-ready patterns, when regex beats parsers, and link to Toollabz regex tester plus JSON formatter/validator companion guides.
Read guide →Developer text pipeline: JSON, YAML, HTML, and CSV (2026)
Learn when to minify vs validate JSON, why YAML needs parse checks, how CSV becomes JSON for mocks, and how HTML formatting and API URL probes fit incident workflows on Toollabz.
Read guide →JWT expiry, timestamps, and honest API health probes (2026)
Explain JWT exp and clock skew, pair expiry checks with Unix timestamps, clarify decode vs verify, and show how Toollabz API URL checker suggests curl probes without fake live HTTP inside sync tools.
Read guide →
Practical scenarios
People who care about broken link checker use Broken Link Pattern Checker as a planning sandbox: Trackers sometimes rewrite URLs - inspect final HTML, not just CMS preview.
Continue in the Developer tools collection or the glossary. Related calculators in this session: Robots.txt Generator, Meta Tag Analyzer, .htaccess Redirect Generator, URL Encoder/Decoder, Regex Tester, API URL Checker (curl helper).
Key formula explained
How the calculation works
The Formula
Flag non-http(s)/mailto/tel/relative href patterns including javascript: pseudo-links- HTML (optional): the value you enter for html.
- Extra URLs (one per line, optional): the value you enter for extra urls.
| This tool | Flag non-http(s)/mailto/tel/relative href patterns including javascript: pseudo-links |
|---|---|
| Related intent: broken link checker | See paired tools for broken link checker-each page documents its own core relationship next to the live form. |
| Related intent: html link validator | See paired tools for html link validator-each page documents its own core relationship next to the live form. |
Core relationship for Broken Link Pattern Checker:
Flag non-http(s)/mailto/tel/relative href patterns including javascript: pseudo-links
Worked check: Paste landing HTML → flag `javascript:void(0)` CTA, OK relative `/pricing` paths, OK `mailto:` support links.
Related calculations
Keep the same assumptions and open a neighbor calculator when your question branches: Robots.txt Generator, Meta Tag Analyzer, .htaccess Redirect Generator, URL Encoder/Decoder. Each page documents its own formula beside the fields.
Learning links: Methodology · Editorial policy · Glossary
Worked real-world example
Paste landing HTML → flag `javascript:void(0)` CTA, OK relative `/pricing` paths, OK `mailto:` support links.
Re-enter the same numbers in the calculator above to confirm the page math matches the interactive result.
Who uses this tool?
People who care about broken link checker use Broken Link Pattern Checker as a planning sandbox: Trackers sometimes rewrite URLs - inspect final HTML, not just CMS preview.
Common mistakes
- For Broken Link Pattern Checker, mismatched units or periods (monthly vs annual, % vs decimal) are the fastest path to a believable wrong answer on broken link checker.
- Watch for this pitfall: Empty hrefs are clickable traps - use buttons for actions instead.
- If you paste the result into a decision doc, note the formula and the page date (2026-07-18) so teammates can reproduce it.
References & sources
Official references for context. Calculator outputs are planning estimates—confirm material decisions with the primary authority or a qualified professional. See our methodology and editorial policy.
- Toollabz methodology — How we document formulas and update pages
- MDN Web Docs
- IETF RFCs
Content last updated 2026-07-18
FAQs
Click a question to expand the answer.
Is the Broken Link Pattern Checker free to use?
Yes, the Broken Link Pattern Checker is completely free with no hidden limits.
Can I use Broken Link Pattern Checker on mobile?
Yes. All tools are optimized for desktop, tablet, and mobile devices.
Does it hit the network?
No - this is a pattern scan only; it cannot detect remote 404 responses.
Are relative URLs OK?
Yes - root-relative and ./../ paths are treated as acceptable patterns.
What about mailto:
mailto: and tel: links are allowed as common patterns.
What does Broken Link Pattern Checker calculate in plain English?
Static scan for risky href schemes and malformed URLs before you pay for a full crawl.
Can you show a worked example for Broken Link Pattern Checker?
Paste landing HTML → flag `javascript:void(0)` CTA, OK relative `/pricing` paths, OK `mailto:` support links.
What are the most important tips when using Broken Link Pattern Checker?
Trackers sometimes rewrite URLs - inspect final HTML, not just CMS preview. Empty hrefs are clickable traps - use buttons for actions instead. Pair with log-based 404 monitoring after launches.
Next step
Open the full directory, browse your hub collection, or jump back to this category. Bookmark the page if you use it often.
Built and maintained by Imtiaz Ahmad
Founder and lead engineer | Content updated July 18, 2026
See methodology and editorial policy.