Web Tools
Meta tags, robots.txt, redirects and web helpers — private, in your browser
Generate meta and Open Graph tags, robots.txt, sitemaps, schema markup and redirect rules, build UTM links, and look up status codes, MIME types and subnets. 13 free tools that run on your device — no signup, no limits.
All web tools
Popular tools
- Meta Tag GeneratorBuild the title, description, robots and canonical tags for a page and preview the Google result.
- Open Graph GeneratorWrite og: and Twitter Card tags and see how the link will look when it is shared.
- Robots.txt GeneratorBuild a robots.txt, test a URL against it, or check one you already have.
- UTM Link BuilderAdd utm_source, medium and campaign to any link, one at a time or from a CSV.
SEO & meta
6 toolsMeta Tag Generator
Build the title, description, robots and canonical tags for a page and preview the Google result.
Open Graph Generator
Write og: and Twitter Card tags and see how the link will look when it is shared.
Schema Markup Generator
Build valid JSON-LD for FAQs, articles, products, events, recipes and more, with field warnings.
Robots.txt Generator
Build a robots.txt, test a URL against it, or check one you already have.
Sitemap XML Generator
Turn a URL list or CSV into a valid sitemap.xml, split big ones, or validate yours.
Redirect Generator
Write 301, 302, 307 and 308 redirects for Apache, nginx, Netlify, Vercel or Cloudflare.
Links & HTTP
4 toolsUTM Link Builder
Add utm_source, medium and campaign to any link, one at a time or from a CSV.
URL Parser
Split any URL into its parts, edit one and rebuild, or encode and decode text.
HTTP Status Codes
Every HTTP status code from 100 to 511, with causes, SEO impact and an example.
MIME Types Lookup
Find the MIME type for a file extension, or the extensions for a type, plus a Content-Type builder.
Network & browser
3 tools13 tools shown
Workflows
Common jobs, done in a few steps
Launch a new site
Write the page tags, the social card, then tell crawlers what to fetch.
Run a campaign
Tag every link so analytics can tell your channels apart.
Move a site
Write redirect rules for the old URLs in the format your server uses.
Lock down headers
Build a Content-Security-Policy and start in report-only mode.
Why Nelstack
Fast, private web tools
What you type stays on your device
Every tool runs in your browser, so URLs, domains and campaign names are never uploaded or stored.
No crawling of your site
We never fetch your pages. Output is generated from what you enter, so test it on your own site before you ship.
Warnings that explain themselves
Length meters, missing fields and risky settings are flagged with a plain reason, not a vague score.
Honest about the limits
Robots.txt is advisory and structured data does not guarantee rich results. The tools say so where it matters.
No caps or signup
No daily quota, no account and no watermark on anything you generate.
Built for phones too
Inputs come first on small screens, with touch-friendly controls and no sideways scrolling.
Looking for another kind of tool?
These live in their own tool areas and work the same private, in-browser way. The slug maker is in Text Tools, URL encoding in Security Tools, JSON and XML in Data Tools and image resizing in Image Tools.
- Text to SlugTurn titles into clean URL slugs, in Text Tools
- URL Encode / DecodePercent-encode and decode URLs, in Security Tools
- JSON to XMLConvert JSON to XML, in Data Tools
- Data ToolsConvert JSON, CSV, Excel, YAML, XML and TOML
- Image ToolsResize and crop images for social cards
- Text ToolsCounters, case converters and text utilities
Web Tools FAQ
Are these web tools really free?
Yes. Every web tool here is free with no signup, no daily limit and no watermark. Generate as many meta tag sets, robots.txt files or redirect rules as you like.
Do you fetch or crawl my website?
No. Everything runs in your browser and the output is generated only from what you type or paste. We never request your site, so test the result on your own pages and in the search engines' own testing tools.
Is robots.txt a way to keep pages private?
No. Robots.txt is a polite request that well-behaved crawlers follow, and it is public for anyone to read. It does not stop a page from being visited or even indexed if it is linked elsewhere. Use authentication or a noindex rule for anything that must stay out of search.
Will structured data give me rich results?
Not by itself. Valid structured data makes a page eligible, but search engines decide whether to show rich results. Check your markup in Google's Rich Results Test and only mark up content that is actually visible on the page.
Does anything I enter get uploaded or stored?
Nothing is sent to a server. URLs, campaign names, domains and policies stay on your device, which is why the tools work offline once the page has loaded.
Where are the slug maker, encoders and image resizer?
The text-to-slug tool lives in Text Tools, URL encoding and hashing live in Security Tools, JSON, XML and query-string conversion live in Data Tools, and resizing images for social cards lives in Image Tools. They all run privately in your browser too.