Most lists of free website tools are written backwards. Someone collects forty tools, sorts them into categories, and you are left to work out which of them solves the problem sitting in front of you. After enough years of auditing other people's sites, I have found the opposite approach far more useful: start from the handful of problems that genuinely come up every week, and keep exactly one good tool for each.

That is what this page is. It is organised by the question you are trying to answer, not by product category, and for each one I explain what to check first, which tool does it, and when a free tool is not the right answer at all. The tools are ours, built for CachePlex because we kept needing them, but I have been honest about where Google's or Meta's own tools are the better choice.

If you would rather have the whole set as one list you can bookmark, we keep it on GitHub as Awesome Free Web Tools, with a short description of each tool and the questions it answers. This article is the reasoning behind that list.

"Why does my link look wrong when I share it?"

This is, by a distance, the question we are asked most. Someone shares a product page in a WhatsApp group and it shows the homepage banner. A new blog post goes out on LinkedIn with no image at all. A client's Slack channel shows last month's headline.

Almost every one of these comes down to Open Graph tags: the og:title, og:description and og:image lines in a page's head that every messaging app and social network reads when a link is pasted. The Share Preview Checker reads those tags the way the apps' crawlers do, downloads the share image to confirm it actually loads, and shows an approximate preview for WhatsApp, Facebook, LinkedIn, X, Discord, Slack, Telegram and iMessage side by side.

Two things are worth knowing before you start changing tags. First, if the checker shows the right image but the app still shows the wrong one, your page is fine and the app is showing a cached copy. Each platform clears its cache differently, and our guide to a link preview showing the wrong image walks through every one. Second, each app has its own quirks, so there are dedicated pages for the awkward ones: the Discord embed checker explains why an embed shows a thumbnail instead of a large image, the Telegram page covers the bot that refreshes its stored preview, and the X card checker exists because X's own Card Validator stopped showing previews in 2022.

Where the official tool is better: when you need Facebook or LinkedIn to forget an old preview, use Meta's Sharing Debugger or LinkedIn's Post Inspector. No third-party tool can clear another company's cache, whatever it claims.

One pattern I see constantly is a preview problem that is really a template problem. If one product page is missing its image, the theme usually leaves every product page missing it. That is why the site-wide preview scan exists: give it a domain and it reads your sitemap and checks the pages in one pass, so a broken template shows up as a pattern rather than a surprise.

"Why isn't this page showing up in Google?"

Before any tool, a word on order. If a page is not indexed, ranking advice is irrelevant, and the authoritative answer about indexing lives in Google Search Console, not in any third-party checker. Use Search Console's URL Inspection first. Use the tools below to understand why it says what it says.

In the order I actually work through them:

  • Is the page allowed to be crawled? A single stray Disallow line in robots.txt can hide a whole folder, and I have seen it happen after a staging site was copied to production. The Robots.txt Checker parses the file and flags rules that block more than you intended. If you need to write one from scratch, the Robots.txt Generator produces a clean file without the classic mistakes. Our explainer on what robots.txt does and how to check it covers the edge cases.
  • Can search engines find the page? If it is not in your sitemap and nothing links to it, discovery is slow. The Sitemap Validator checks structure and URLs, and if Search Console reports that it couldn't fetch your sitemap, that guide explains what each error means.
  • Is the page itself any good? The SEO Analyzer scores the on-page basics (title, description, headings, images, links) and tells you what to fix first. It will not tell you whether your content deserves to rank. Nothing automated can, and you should be suspicious of any tool that implies otherwise. For a structured way to do it yourself, see how to run an SEO audit on your own site.
  • Is the structured data valid? Rich results such as star ratings, FAQs and product prices depend on schema markup being correct. The Schema Checker finds JSON-LD, Microdata and RDFa on any URL and flags what is broken. Google's Rich Results Test is the final word on eligibility; ours is quicker for seeing everything a page declares.
  • Is the certificate healthy? An expired or misconfigured certificate puts a full-page warning in front of every visitor. The SSL Checker shows expiry, issuer, chain and a grade, and our guide to the "Your connection is not private" error explains the common causes.

If the issue is click-through rather than ranking, it is usually the snippet. The Meta Tag Generator drafts titles and descriptions from plain page details, and the guide to writing meta descriptions that get clicked explains what actually earns the click.

"Why are our emails going to spam?"

This one costs businesses real money and is almost never about the subject line. In my experience it is DNS: a missing or broken SPF record, no DKIM signature, or no DMARC policy, and since early 2024 Gmail and Yahoo have required all three from bulk senders.

The Email Deliverability Checker takes a domain and checks SPF, DKIM, DMARC, MX and blacklist status, then tells you which record to fix. The subtle failure it catches is SPF's ten-lookup limit: every include: you add for a new email service costs lookups, and once you pass ten the whole record fails silently. The full explanation is in why your emails go to spam.

"Why won't this image open, or upload?"

Image formats cause a surprising amount of lost time for people who are not designers, mostly because the error messages are useless.

A note on privacy, because people rightly ask. The HEIC, WebP, PDF and background-removal tools process files on your own device; nothing is uploaded. For client photos, scanned documents or anything personal, that is the main reason to prefer them over upload-based converters.

"I need this as a PDF" (or out of one)

Two tools cover nearly every case. JPG to PDF combines photos or scans into one document, with page order and rotation, which is what most people need for applications and claims; our guide on combining photos into one PDF covers A4 versus Letter and shrinking a file that is too big to upload. PDF to JPG goes the other way, at up to 300 DPI for print.

The launch checklist nobody remembers

Every new site or app needs the same small assets, and they are always remembered the night before launch:

Writing and content checks

The Readability Checker gives you Flesch Reading Ease and grade level, which is a useful sanity check rather than a target to optimise; what those scores actually mean explains why. The AI Text Detector estimates whether text was machine-written. Treat any AI detector's verdict as a probability, not proof: they are wrong often enough that you should never make a decision about a person's work on the score alone.

For developers

The everyday utilities are here because they are quicker than opening an editor: the JSON Formatter and JSON Validator for API responses, and the HTML and CSS minifiers for quick one-off jobs. For anything that ships to production, minify in your build pipeline instead.

What I deliberately left out

There are no rank trackers, backlink databases or keyword research suites on this list. The good ones cost money because the data is expensive to collect, and the free versions are usually too limited to base decisions on. If you need that data, pay for one proper suite rather than stitching together free trials.

I have also left out anything that duplicates what Search Console, Google Analytics or the platforms' own debuggers already do well. A free tool earns its place by answering a question faster or more clearly than the official option, not by existing.

Keeping the list somewhere useful

Articles go out of date; lists can be maintained. The complete set, with a one-paragraph description of each tool, the questions it answers and a direct link, is kept on GitHub as Awesome Free Web Tools, and there is a readable version of the same list at its GitHub Pages site. When we add a tool or a guide, that is the first place it appears. If you find a broken link or want to suggest a tool, opening an issue on the repository is the quickest way to reach us.

Short version

Start from the question, not the tool. Shared links look wrong: check the Open Graph tags, then clear the platform's cache. Page not found in Google: Search Console first, then robots.txt, the sitemap and the page itself. Emails in spam: SPF, DKIM and DMARC before anything else. Files that won't open or upload: convert them properly rather than renaming them. Everything mentioned here is free to use and listed, with descriptions, in the GitHub list, or on our tools page.