Free Online SEO, Text and File Conversion Tools
NasSeoTools is a collection of free browser-based utilities for the small, awkward jobs that come up while running a website: checking what a domain resolves to, converting a file into the format a client actually asked for, working out whether a password is weak, or turning a unit of measurement into one your reader understands. Nothing needs an account and nothing needs installing.
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Log inText Analysis Tools
Count words, compare cases, reverse or restyle a block of text, pull the text back out of an image, and rewrite or paraphrase a draft. Useful when you are working to a length limit or cleaning up copy that arrived in the wrong format.
Password Managment Tools
Generate a password that will survive a dictionary attack, check how weak an existing one is, and produce the hash formats that WordPress and other applications store rather than the password itself.
Online Calculators
Everyday arithmetic that is easy to get subtly wrong: percentages, averages, sales tax, discounts off a marked price, probability, and the number of days between two dates.
Unit Converters
Convert between metric and imperial and between the units used in different trades — weight, temperature, speed, length, area, volume, pressure, power, torque, time and data size. Each converter shows the formula it used so you can check the result.
- Power Converter
- Weight Converter
- Temperature Converter
- Electric / Voltage Converter
- Area Converter
- Length Converter
- Byte/Bit Converter
- Time Unit Converter
- Pressure Converter
- Speed Converter
- Volume Converter
- Torque Converter
- Kilograms to Pounds Converter
- Pounds to Kilograms Converter
- Celsius to Fahrenheit Converter
- Fahrenheit to Celsius Converter
- MPH to KM/H Converter
- KM/H to MPH Converter
- CM to Feet Converter
- Feet to CM Converter
- Miles to Kilometers Converter
- Kilometers to Miles Converter
- Liters to Gallons Converter
- Gallons to Liters Converter
Development Tools
Format, validate, minify and read the file types that sit behind a site: JSON, XML, HTML, CSS and JavaScript. Includes editors and viewers for when you need to see the structure rather than edit it.
Tags Tools
Write and check the markup that decides how a page looks when it is shared or listed — meta titles and descriptions, Open Graph tags and Twitter cards — and analyse the tags a page is already sending.
Domains Tools
Find out what is actually true about a domain rather than what its owner claims: how old it is, who hosts it, which IP it resolves to, what its DNS records say, whether it appears on a blacklist, and what authority it has picked up.
Image Tools
Change an image into the format something else insists on, make it smaller without it looking wrong, resize it to fixed dimensions, build a favicon from a logo, or find out where else a picture has been published.
Binary Converters
Move between the representations a machine uses and the ones a person reads: text to binary, binary to ASCII, hexadecimal to binary, decimal to hex and back again. Handy for debugging encoding problems and for coursework.
Website Management Tools
The checks you run on a site you are responsible for: an SEO score, a screenshot as a crawler sees it, a sitemap, a ping to the indexers, a theme detector and a URL opener for testing several pages at once.
- Website SEO Score Checker
- Website Screenshot Generator
- Online HTML Viewer
- WordPress Theme Detector
- Twitter Card Generator
- Open Graph Generator
- XML Formatter
- HTML Minifier
- Javascript Minifier
- CSS Minifier
- Online Ping Website Tool
- URL Opener
- URL Encoder Decoder
- Base64 Encode Decode
- QR Code Generator
- XML Sitemap Generator
- HTML Editor
Who these tools are for
Most of the people using these pages are doing someone else's job at the same time as their own. A freelance writer who needs a word count and a readability pass before invoicing. A small-business owner checking why their site dropped off the first page. A developer who just wants to see whether a JSON payload is valid without pasting it into a service that keeps a copy. A student converting Celsius to Fahrenheit for homework. The tools are grouped by the kind of problem rather than by technology, so you can usually find the right one without knowing what it is called.
How the tools work
Where a job can be done in your own browser it is: the unit converters, the binary and ASCII converters, the text utilities and the calculators all run locally, so what you paste in is never sent anywhere. Tools that genuinely need a server — domain lookups, DNS records, image and PDF conversion, screenshots — send only the input required to do the job. Converted files are removed from the server automatically once they have been generated and downloaded.
Where to start
If you are here for a specific job, the category blocks above are the fastest route. The full tools index page lists everything in one place, and the blog covers the longer questions the tools cannot answer on their own — how search engines actually treat duplicate content, what domain authority does and does not measure, and when a redirect is the wrong fix. If something you need is missing, the contact page is the place to ask.