Open-source core · v0.1 for macOS

A linter for your website.

Truelint crawls your site the way a linter reads code: every page, every link, 125 checks, each with a plain-English fix. It runs on your Mac, in your terminal, or in a browser, and a million URLs fit in 210 MB of memory.

Download for macOS Compare with Screaming Frog

Free up to 1,000 URLs per crawl · No account · Your crawls never leave your machine

Truelint workspace: the Internal tab grid with status codes, the Issues pane grouped by severity, and a URL's detail pane

125checks, each with how-to-fix guidance written for developers

1MURLs crawled in 307 seconds on a laptop, 210 MB peak memory

9×faster than Screaming Frog on the same 20,000-URL site, 14× less memory

8 MBinstaller. Single-file crawls you can open, share and compare later

What it finds

Every technical SEO problem, with the fix attached.

Grouped by severity, filtered by tab, exported in one click. The wording was written for the person who has to change the page.

Broken links and redirect chains

4xx and 5xx targets, chains, loops, meta refreshes, mixed content, and which pages link to each of them.

Duplicate and thin content

Exact and near-duplicate detection on the main content only, so a shared sidebar never counts twice.

Canonicals, directives, hreflang

Missing, conflicting and non-indexable canonicals; noindex leaks; hreflang without return links; sitemap orphans.

Structured data validation

Required and recommended properties for 35 schema.org types, rich-result eligibility per item.

JavaScript rendering

Renders with Chrome, diffs raw versus rendered titles, links and content, and catches JavaScript-only redirects.

Accessibility and mobile

axe-core on every rendered page with WCAG tags; content wider than the screen, tiny text, tap targets.

Extraction, search, AI

CSS, XPath and regex extraction; source-code search; per-page prompts to your own OpenAI, Anthropic or Ollama.

Compare crawls

Open two crawls of the same site and see exactly which pages changed, appeared, or broke since last time.

How it works

Three steps. Minutes, not afternoons.

Enter a URL

Or paste a list. Configure scope, rendering, extraction and auth if you need them; the defaults are right for most sites.

Read the Issues pane

Findings grouped by severity as the crawl runs. Click one to filter the grid to every affected page, with the specific detail per URL.

Hand over the fix

Export the view, a rule, or one of the bulk reports. Re-crawl next month and compare to prove the work landed.

Measured, not claimed

Same site, same laptop, same five threads.

20,000 HTML pages served locally, JavaScript rendering off, MacBook Pro 16 GB. Screaming Frog 22.2 with default memory. Full comparison and caveats.

Time to crawl 20,000 URLs

Truelint4.6 s

Screaming Frog42.3 s

Peak memory

Truelint72 MB

Screaming Frog1,009 MB

Three front doors, one engine

Desktop, terminal, or browser.

Desktop app

Native macOS app. Crawls are single files you can open, share and compare later. Windows and Linux builds are coming.

Command line

truelint crawl https://example.com, then export, compare or schedule. Runs in CI and on servers. The crawler core is open source under Apache-2.0.

Browser and API

Self-host the same interface with an HTTP API, live progress events, and scheduled crawls that run without your laptop open.

Guides

Practical technical SEO, written by people who crawl for a living.

Screaming Frog alternative: Truelint compared, with measurementsA measured comparison of Truelint and Screaming Frog SEO Spider on the same 20,000-URL site: speed, memory, checks, price, and what each one is better at.The technical SEO audit checklist (2026): 40 checks in the order that mattersA working technical SEO audit checklist, ordered by impact: crawlability, indexability, duplication, links, content, speed and structured data — with what to look for and how to fix each item.How to find broken links on a website (and which ones to fix first)Broken links cost rankings, trust and sales. How to find every 404, 5xx and dead redirect on your site, see which pages link to them, and fix them in the right order.Duplicate content: how to find it, why it happens, and how to fix it without losing rankingsExact and near-duplicate pages split rankings and waste crawl budget. Where duplicates come from on real sites, how to detect them properly (main content only), and the fix for each cause.Canonical tags: the complete guide to rel=canonical, with the mistakes that break itWhat a canonical tag does, when you need one, the seven ways sites get it wrong, and how to audit every canonical on a site in one crawl.Redirect chains and loops: how they happen, what they cost, and how to fix themEvery redirect hop costs time, crawl budget and a slice of link equity. How chains and loops form on real sites, how to find every one with its sources, and the three-step fix.

All guides →

Crawl your site in the next five minutes.

Free up to 1,000 URLs. No account. 8 MB download.

Download for macOS