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Tools

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Technical SEO

Check how search engines access and read your website.

Robots.txt checker and policy builderTest live crawler access, then generate, validate, path-test, copy, and download a standards-aware UTF-8 policy.
Robots.txt policy comparisonCompare two complete policy sources, duplicate and unsupported declarations, and deterministic path outcomes for a supplied crawler token without uploading either file.
Robots meta tag and X-Robots-Tag generatorBuild page-level robots directives, HTTP headers, Apache snippets and Nginx snippets, then check pasted tags or headers for conflicts and unsupported tokens.
URL indexability checkerCheck HTTP status, redirects, canonical URLs, robots directives, metadata, structured data, hreflang, and social preview tags.
On-page SEO checkerInspect titles, descriptions, headings, language, viewport, image alternatives, links, schema, hreflang, and social metadata from live HTML.
Technical SEO site audit and action ledgerCrawl up to 25 same-site pages, map anchors, follow states, depth, URL path groups, redirects, and broken targets, then assign evidence-backed tasks with browser-private workflow fields and exports.

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Metadata & page markup

Prepare how your pages appear in search and social sharing.

Meta tag generator and search appearance toolImport a public page or build escaped title, description, canonical, robots, Open Graph, and X card tags with local HTML and JSON exports.
SERP preview and title checkerPreview title links, meta descriptions, source labels, and display URLs with approximate desktop or mobile pixel-width checks and complete exports.
Open Graph and X card checkerBuild Open Graph and X card tags, preview social share fields, and check pasted metadata for missing images, alt text gaps, duplicates, invalid URLs, and template leftovers.
Structured data generator and JSON-LD validatorBuild common schema.org entities or inspect pasted JSON-LD with bounded syntax, graph, URL, and type-specific checks.
Live structured data and JSON-LD checkerFetch one public page, inspect retained JSON-LD script blocks, graph nodes, duplicate @id values, schema.org context, article/product/breadcrumb fields, microdata, RDFa, and exportable findings.
Hreflang generator and reciprocal link checkerBuild matching HTML, HTTP header, and XML sitemap alternate sets, then inspect each public page for self-reference and return links.

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Keywords & content

Organize your research and improve the content you publish.

Keyword generator and intent ideasGenerate phrase-match, same-term, question, comparison, local, commercial, content, source-text, and custom-modifier ideas from your own seeds without fabricated metrics.
Keyword grouper and topic clusteringNormalize and deduplicate up to 2,000 phrases, build transparent lexical topic groups, review multilingual rule-based intent cues, and export the complete retained list.
Keyword gap and portfolio comparisonCompare one baseline with up to three supplied research lists, account for duplicates and rejected lines, and export the complete exact phrase-presence matrix.
Target keyword checker and page comparisonCompare up to ten supplied phrases across live URL, title, description, H1, and image-alt evidence for as many as five pages.
Word count and keyword density checkerCount supplied text, Markdown, or HTML for words, sentences, top terms, n-grams, target phrase density, reading-time indicators, and readability estimates without a content score.
Reference-backed SEO content brief and draft editorReview your draft against supplied phrases, questions, and reference texts with exact lexical coverage, transparent structural ranges, and complete Markdown, CSV, and JSON exports.

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Sitemaps & crawler files

Build and validate the files that help crawlers find your pages.

Sitemap tree explorerFollow same-host sitemap indexes, review discovered URLs, and check selected terminal responses while keeping sitemap inclusion separate from crawling and indexing.
XML sitemap validator and URL health checkerValidate URL sets, sitemap indexes, gzip decoding, dates, duplicates, unsafe doctypes, and nested references, then run bounded live HEAD checks for selected sitemap URLs.
Sitemap discovery comparisonCompare two complete sitemap exports locally and retain exact URL, source-document, lastmod, scope, and truncation differences.
RSS and Atom feed parserExtract URL, title, publication date, update date, category, author, and enclosure evidence from supplied RSS, Atom, or RDF feed source with local CSV, TXT, and JSON exports.
llms.txt checker, validator and generatorInspect a root or scoped v2 file, validate its exact Markdown order, resolve file-list links, check destinations, and generate clean UTF-8 source.
AI crawler policy checkerMap one path across search indexing, AI search, user retrieval, model training, and open-corpus robots policies without making a crawler-visit claim.

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Performance & security

Review resource delivery, page performance, and server settings.

PageSpeed Insights and Core Web Vitals checkerRun Google Lighthouse for mobile or desktop, keep lab and field evidence separate, and export category scores, timings, opportunities, diagnostics, versions, and timestamps.
Mobile SEO and viewport checkerCheck live source evidence for viewport setup, language, UTF-8 clues, image alternatives, image dimensions, blocking resource candidates, resource hints, third-party resources, HTTPS, redirects, and crawler access without a mobile-rendering score.
Font legibility, size and zoom checkerInspect one public page plus retained CSS for small font-size declarations, tight line-height, zoom restrictions, text-size-adjust rules, font-display gaps, CSS imports, stylesheet fetch status, and exportable findings.
HTTP header and cache policy inspectorFollow a public URL to its terminal response and inspect exact cache directives, freshness, validators, crawler controls, content metadata, redirects, and common security declarations.
HTTP response header comparisonRun two independent HEAD checks and compare exact terminal status, redirects, cache fields, validators, crawler controls, content metadata, and common browser security declarations.
GZIP, Brotli and cache checkerCheck exact response headers for Content-Encoding, Vary: Accept-Encoding, Cache-Control, immutable assets, validators, declared file size, redirects, and response state.

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Analysis & reporting

Compare the data you have and turn findings into a plan.

Search Console performance and period comparisonCompare matching query or page exports across clicks, impressions, CTR, and average position with duplicate accounting and complete local exports.
Rank history and SERP snapshot comparisonCompare matching provider exports across position, ranking URL, SERP features, engine, location, and device while preserving every input and evidence limit.
SERP feature and AI Overview comparisonCompare supplied feature exports across triggered SERP features, owned features, AI Overview citations, featured snippets, local packs, engine, location, device, and language.
Website analytics and traffic period comparisonCompare supplied page, source, channel, geography, or technology exports across sessions, users, views, conversions, and transparent AI referral cues.
Traffic benchmark and channel comparisonCompare supplied site, channel, country, and device benchmark exports across visits, users, views, conversions, and share-of-input without invented market share.
Paid search and PPC ad comparisonCompare supplied paid keyword, ad copy, landing-page, position, CPC, traffic, and cost exports without claiming live ad-network history.

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Submission & monitoring

Connect your website and work with search provider tools.

IndexNow submissionGenerate or verify an IndexNow key, submit same-site URL batches, and review the provider response without treating it as crawl or index confirmation.
Google Indexing experimentUse official eligible types—or run an explicitly labeled ordinary-page experiment with your own service account.
Google index evidenceRead Google’s stored URL Inspection view with crawl and retrieval timestamps kept separate.

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Research & resources

Explore crawler information and document your observations.

Open Search ObservatoryResearch public crawler, archive, field-performance, identity, and source-availability evidence.
Domain evidence profileBuild a public, coverage-aware domain snapshot where every scored point remains attached to its evidence.
Evidence LabKeep a private change history, run repeatable experiments, and export signed records that can be checked for later changes.
Crawler identity directoryBrowse documented crawler identities and learn what each bot is designed to do. A directory listing does not prove that a bot visited your site.

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Platform

Workspaces

My sitesVerification, audits, and change history
Portfolio monitorBrowser-private URL groups and snapshots
Opportunity plannerBrowser-local task planning from imported evidence
SEO alertsBrowser-local alert rules for imported evidence
Traffic benchmarkBrowser-local site and channel movement comparison
Content performance reviewBrowser-local refresh and consolidation lanes
Evidence labAppend-only private research records
Site auditBounded technical and internal-link crawling

Open research

Search ObservatorySource-separated public observations
Crawler directoryDocumented crawler identities and operators
AI crawler policySearch, retrieval, and training controls

Resources

Use OpenWebmaster

All free toolsBrowse the complete public toolkit
MethodologyEvidence definitions and limits
Crawler ROI calculatorModel crawl cost with your inputs

Crawler access

OpenWebmaster robots.txtReview the live crawler policy
XML sitemap indexBrowse public discovery files
Sitemap toolsGenerate, validate, and explore XML

Preferences

Make OpenWebmaster yours

Language, color, reading size, and motion stay on this device.

Site languageColor themeText sizeMotion

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OpenWebmaster
Free SEO Portfolio Monitor

URL portfolios · private browser snapshots

Group and monitor the URLs that matter

Build competitor, client, campaign, author, regional, or experiment portfolios from your own URLs. OpenWebmaster preserves exact scope, grouping, and coverage evidence without inventing traffic, rank, authority, or backlink metrics.

URL LIMIT: 1,000
HOST LIMIT: 10
SNAPSHOTS: 12

PORTFOLIO SETTINGS

Define the monitoring scope

Portfolio name

Target modePath grouping depthReview cadence

Evidence sources to attachTechnical crawlSitemap discoveryPageSpeedSearch ConsoleAnalyticsBacklinksCrawler logsAI visibility

URLs with optional segment, owner, and tagsFragments are removed. Query strings remain part of exact URL targets. URLs with credentials are rejected.

Import snapshot

LIVE PORTFOLIO

Coverage-aware view

Technical crawl, Sitemap discovery, Search Console

▦

Ready for a real URL set.

No sample portfolio appears here. Add public URLs from a campaign, competitor set, author group, regional folder, or SEO experiment.

SAVED SNAPSHOTS

Compare the current portfolio with earlier retained scope

Baseline snapshot

Snapshots stay in this browser until you export or remove them.

Evidence boundary

A portfolio snapshot proves only what was retained from your submitted URL list at a point in time. Scheduled crawling, team sharing, email alerts, provider sync, and durable client permissions require authenticated infrastructure.

OpenWebmasterby Mello Zone

Practical SEO tools for people who care about their websites.

Explore the source ↗

Explore tools

Technical SEO Keywords & content Metadata & markup Performance & security Analysis & reporting All free tools

Website essentials

Robots.txt checker XML sitemap validator Meta tag generator Structured data SERP preview Security headers

Platform

My websites IndexNow Search Console Report builder Opportunity planner Evidence Lab

Resources

Search Observatory Crawler directory Our methodology AI crawler policies llms.txt Security contact

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