# ContentSERP Free AI & SEO Tools > Free, deterministic AI & SEO engineering tools that run instantly in your browser. Built by ContentSERP to replace tedious manual work for marketers, developers and operators. > Hub: ContentSERP offers 22 free, deterministic tools for keyword research, technical SEO, structured data, media editing, backlink analysis and translation. Most run 100% client-side with no signup and no cost. Canonical hub: https://contentserp.in/seo-tools Sitemap: https://contentserp.in/seo-tools/sitemap.xml ## Agent & Dev - [Schema & llms.txt](https://contentserp.in/seo-tools/schema-generator): Free structured-data generator: build valid JSON-LD (FAQ, Article, Product, Software, Breadcrumb), Open Graph meta tags and an llms.txt file to make your site AI-search ready. - Primary keyword: free seo marketing tools - Execution: Zero-Token (Instant) - [llms.txt Generator](https://contentserp.in/seo-tools/llms-txt-generator): Free llms.txt generator: build a spec-compliant llms.txt file that gives ChatGPT, Claude and Perplexity a curated map of your key pages, with sections, links and notes. Copy or download instantly. - Primary keyword: llms txt generator - Execution: Zero-Token (Instant) - [FAQ Schema](https://contentserp.in/seo-tools/faq-schema-generator): Free FAQ schema generator: build valid FAQPage JSON-LD from your questions and answers, preview the FAQ, and export schema that helps Google and AI answer engines read and cite your page. - Primary keyword: faq schema generator - Execution: Zero-Token (Instant) ## SEO & GEO - [Keyword Research](https://contentserp.in/seo-tools/keyword-research): Free keyword research tool: expand seed terms into hundreds of buyer-intent and question keywords with instant volume estimates, difficulty scores and CSV export. No signup. - Primary keyword: free keyword research tools - Execution: Zero-Token (Instant) - [SEO Audit](https://contentserp.in/seo-tools/seo-audit): Free SEO audit tool: paste any URL to instantly score title, meta, headings, links, images and technical signals, with prioritised, fix-ready recommendations. - Primary keyword: free seo audit tools - Execution: Guarded Low-Token - [Backlink Analyzer](https://contentserp.in/seo-tools/backlink-analyzer): Free backlink checker: paste your link export to analyse referring domains, anchor-text distribution, dofollow vs nofollow and toxic-link signals — instantly, in the browser. - Primary keyword: free backlink checker tools - Execution: Guarded Low-Token - [SERP Preview](https://contentserp.in/seo-tools/serp-preview): Free SERP preview tool: see exactly how your title, URL and meta description will look in Google search results on desktop and mobile, with pixel-accurate truncation warnings. - Primary keyword: free serp preview tool - Execution: Zero-Token (Instant) - [Meta Description](https://contentserp.in/seo-tools/meta-description-generator): Free meta description generator: turn a focus keyword and benefit into several Google-ready snippets with live pixel and character length checks, plus copyable title tags and HTML head. No signup. - Primary keyword: meta description generator - Execution: Zero-Token (Instant) - [Keyword Density](https://contentserp.in/seo-tools/keyword-density-checker): Free keyword density checker: analyse any text for 1-word and 2-word phrase density, spot keyword stuffing, and get Flesch readability, word count and reading time instantly. No upload, no signup. - Primary keyword: keyword density checker - Execution: Zero-Token (Instant) - [robots.txt Generator](https://contentserp.in/seo-tools/robots-txt-generator): Free robots.txt generator: build a valid robots file with one-tap allow/block rules for AI crawlers like GPTBot, ClaudeBot and Google-Extended, then test any URL against your rules instantly. No signup. - Primary keyword: robots txt generator - Execution: Zero-Token (Instant) - [Hreflang Generator](https://contentserp.in/seo-tools/hreflang-generator): Free hreflang generator: create correct reciprocal hreflang tags in HTML or XML-sitemap form with x-default and self-reference, plus instant validation for duplicate or invalid language codes. - Primary keyword: hreflang tag generator - Execution: Zero-Token (Instant) - [Alt Text Generator](https://contentserp.in/seo-tools/alt-text-generator): Free alt text generator: turn what is in an image into concise, screen-reader-friendly alt text under 125 characters, with keyword stuffing, “image of” filler and file-name leaks flagged. No upload. - Primary keyword: alt text generator - Execution: Zero-Token (Instant) - [Content Decay](https://contentserp.in/seo-tools/content-decay-checker): Free content decay checker: score a page’s freshness from its publish date, time-sensitive wording and outdated year references, and get a prioritised refresh list. Runs instantly, no signup. - Primary keyword: content decay checker - Execution: Zero-Token (Instant) ## Governance & FinOps - [AI Cost Calculator](https://contentserp.in/seo-tools/ai-cost-calculator): Free AI cost calculator: estimate daily, monthly and yearly LLM API spend from your token usage across popular models, compare providers and find the cheapest option instantly. - Primary keyword: free ai cost calculator - Execution: Zero-Token (Instant) - [AI Readiness (llms.txt)](https://contentserp.in/seo-tools/llms-readiness): Free AI-readiness (GEO) checker: audit any site for an llms.txt file, valid JSON-LD, LLM-crawler robots rules and sitemap so ChatGPT, Claude and Perplexity can cite you. - Primary keyword: free ai seo tools - Execution: Guarded Low-Token ## Content & Operations - [Diagram Maker](https://contentserp.in/seo-tools/diagram-maker): Free online diagram tool: turn plain text into flowcharts, sequence, ER and Gantt diagrams instantly in your browser, then export SVG or PNG. No account, no watermark. - Primary keyword: free online diagramming tools - Execution: Zero-Token (Instant) - [Image Editor](https://contentserp.in/seo-tools/image-editor): Free online photo editor: crop, resize, compress and convert images to JPG, PNG or WebP right in your browser. Your files never leave your device. - Primary keyword: free photo editing tools online - Execution: Zero-Token (Instant) - [Audio Editor](https://contentserp.in/seo-tools/audio-editor): Free online audio editor: trim, normalise volume and convert MP3, WAV, M4A or OGG files in your browser with a live waveform. No upload, no install. - Primary keyword: free audio editing tools - Execution: Zero-Token (Instant) - [Translation](https://contentserp.in/seo-tools/translation): Free online translation tool: translate text between 50+ languages with tone and glossary controls. Instant results with a transparent, rate-limited free tier. - Primary keyword: free translation tools online - Execution: Guarded Low-Token - [OCR Text Extract](https://contentserp.in/seo-tools/ocr): Free online OCR tool: extract selectable text from images and scans (JPG, PNG, TIFF, WebP) in 100+ languages. Runs 100% in your browser — your files are never uploaded. - Primary keyword: free ocr tools online - Execution: Zero-Token (Instant) - [Readability Score](https://contentserp.in/seo-tools/readability-score-calculator): Free readability score calculator: check any text against six formulas including Flesch Reading Ease, Flesch-Kincaid grade, Gunning Fog, SMOG and ARI, with the longest sentences and complex words flagged. Instant and private. - Primary keyword: readability score calculator - Execution: Zero-Token (Instant) - [Reading Time](https://contentserp.in/seo-tools/reading-time-calculator): Free reading time calculator: estimate how long an article takes to read, read aloud or skim using adjustable words-per-minute presets, with automatic image and paragraph overhead. No signup. - Primary keyword: reading time calculator - Execution: Zero-Token (Instant) ## Optional (Low-Token) Notes - SEO Audit and Translation use a deterministic core with an optional, rate-limited AI enhancer. - All free-tier scores and estimates are transparent, rule-based and directional.