SpellMistake is live. Seven tools, no account, nothing metered, and no upgrade prompt waiting behind the third click. This post is the tour: what each tool does, where it will let you down, and what we are working on next.
The organising principle is simple. If a job can be done inside your browser, it is done inside your browser — which is why five of the seven never make a network request at all and could not read your text if we wanted them to.
The writing tools
Spell Checker
Paste up to about 19,000 characters and get spelling, grammar and style issues underlined in place, each with one-click fixes. Your browser talks to the LanguageTool API directly, so the text never passes through our servers. Full walkthrough: Spell Checker: How to Catch the Errors Your Eyes Skip.
Open it: Spell Checker.
Word Counter
Live words, characters with and without spaces, sentences, paragraphs and reading time, plus the six terms you are repeating most. Entirely client-side. If you are wondering what number to aim for, Word Counter: How Long Should a Blog Post Really Be? gets into it.
Open it: Word Counter.
Article Rewriter
A rule-based rewriter: a curated synonym dictionary plus around forty wordy stock phrases it trims. No language model, no server call, no cost, and no understanding of your sentence — which is why every change is highlighted for you to check. We are deliberately blunt about its limits in Article Rewriter: What Rewriting Tools Can and Cannot Do.
Open it: Article Rewriter.
The SEO and developer tools
Sitemap Generator
Paste a list of URLs, or point it at an existing sitemap or page and let it pull the list for you, then download valid XML. See Sitemap Generator: How to Create and Submit an XML Sitemap, or How to Build an XML Sitemap by Hand if you want the format itself.
Open it: Sitemap Generator.
Robots.txt Generator
Pick a policy, add your exceptions, download the file. It handles the group syntax that catches people out — rules stranded under the wrong user-agent do nothing at all. Background in Robots.txt Generator: Writing Rules Crawlers Actually Follow.
Open it: Robots.txt Generator.
Page Size Checker
Give it a public address and it measures the HTML plus the scripts, stylesheets and images that page references, sorted heaviest first. This one runs server-side, because browsers refuse to read pages on other domains. What the numbers mean: Page Size Checker: How Heavy Is Too Heavy?
Open it: Page Size Checker.
URL Encoder and Decoder
Percent-encode or decode in both directions, with a breakdown of what a valid URL actually contains. The component-versus-whole-URL distinction is explained in URL Encoder and Decoder: When and Why to Percent-Encode.
Open it: URL Encoder and Decoder.
What touches a server and what does not
We think this is the part worth being precise about, so here is the complete list.
- Never leaves your browser: Word Counter, Article Rewriter, URL Encoder and Decoder, Robots.txt Generator, and the XML generation step of Sitemap Generator.
- Goes straight to a third party: Spell Checker. Your browser posts the text to the LanguageTool API and gets results back. It does not pass through us.
- Goes through our server: Page Size Checker, and the optional URL-fetching step inside Sitemap Generator. We fetch the address you give us and return the measurements. We do not log the addresses.
There is no analytics package on this site, no advertising, and no cross-site tracking. That is also why there is no cookie banner to dismiss — we set no non-essential cookies to ask you about. The privacy policy spells all of this out.
What is next
- A real crawl mode for the sitemap tool. Right now it reads one page. Following internal links to a depth you choose is the obvious next step.
- Total page weight with compression. The size checker measures declared sizes over a bounded sample. Reporting compressed transfer size, and covering more assets, would make the total exact rather than a floor.
- A meta description preview. Character-accurate, with the truncation point marked, because guessing at 155 characters is a silly thing to do by hand.
- More languages in the spell checker. The underlying service supports plenty; we currently expose English only.
If you hit something broken, or want a tool that is not here, the contact page goes straight to a person. That is the fastest route to it being fixed, and it is genuinely how we decide what to build next.