Free tools
Free online SEO tools.
Less busywork.
Prepare content, convert images and inspect markup in one place. Each tool explains what it measures and where your input is processed.
Free to useNo registration required
Clear processingPrivacy explained for each tool
Clear resultsUnderstand every output
Defined scopeKnow what each tool measures
Word counter
Available nowCount words, characters, paragraphs and estimated reading time locally. Your text is not uploaded.
Open word counter
Writing and text
Work with text, encoding and keyword analysis.
Word counterCount words, characters, paragraphs and reading time as you write.
Text case converterConvert text to sentence case, title case, uppercase or lowercase.
Reverse textReverse graphemes, words or lines without breaking emoji.
Keyword density checkerMeasure single-word frequency and exact phrase occurrences in your text.
Base64 encode / decodeEncode and decode UTF-8 text. Base64 is an encoding, not encryption.
Images
Convert, resize and edit images in your browser.
JPG to PNG converterConvert a JPG image into a downloadable PNG without uploading it.
Image to WebP converterCreate a WebP copy and choose the quality setting.
WebP to PNG converterConvert a WebP image into a PNG copy in your browser.
Resize imageSet image dimensions while optionally preserving the aspect ratio.
Compress imageCreate a smaller JPEG or WebP copy and compare output size.
Rotate imageRotate by 90, 180 or 270 degrees without clipping the image.
Crop imageChoose an exact pixel rectangle and download the cropped image.
Image to black and whiteCreate a grayscale copy while retaining transparency in PNG output.
Image alt checkerInspect pasted HTML for missing, empty and descriptive image alt attributes.
Units and values
Convert between different units and values.
HEX to RGBConvert 3-, 4-, 6- or 8-digit hexadecimal colors to RGB or RGBA.
PX to REMConvert pixels to rem using the root font size you specify.
Length converterConvert meters, centimeters, millimeters, kilometers, inches and feet.
Temperature converterConvert Celsius, Fahrenheit and Kelvin with absolute-zero validation.
File size converterConvert decimal and binary storage units with an explicit unit basis.
Markup and sharing
Generate, validate and share markup and social data.
Twitter card generatorGenerate escaped summary or large-image card meta tags.
Open Graph generatorGenerate page-sharing tags with validated URLs and image description.
JSON-LD structure checkerCheck JSON-LD syntax, context, type and common structural fields.
Schema generatorCreate Organization, Article, BreadcrumbList or FAQPage JSON-LD.
AMP validatorValidate pasted HTML with the official AMP project's validator.
SEO research and planning
Research keywords, analyze reports and plan your strategy.
AEO, GEO and SEO checkerCheck a public page URL or pasted HTML for search optimization, answer readiness and signals useful to generative search. Get three checklists with practical fixes.
Domain name length checkerCheck domain and label lengths, including the ASCII form of internationalized names. No availability lookup.
Competitor backlink analyzerAnalyze a CSV export from your backlink provider locally. No live crawl is performed.
Keyword suggestion toolBuild question and intent-based keyword ideas from a seed topic, without invented search volumes.Catalogue Domain Rating lookupLook up owner-supplied scores in the active marketplace. Not live Ahrefs measurements.
Link outreach plannerPrepare a relevant outreach brief and qualified link markup. This does not create external backlinks.Planning a business domain?
Explore naming, registration and domain SEO guidance, then check the length of your shortlist.
Choose by task
Compare SEO tools by input and result
The best tool for your task answers a specific question with data you can inspect. These free online SEO tools help prepare content and compare supplied reports. Use the table to choose an input, understand the result and decide what still needs a manual check.
| Task and tool | Input | Result and scope |
|---|---|---|
| Check an article's lengthWord counter | Article text | Word and character counts, paragraphs and estimated reading time. It does not assess factual accuracy. |
| Review keyword repetitionKeyword density checker | Article text and a phrase | Word frequency and exact phrase occurrences. There is no recommended density or ranking prediction. |
| Check image descriptionsImage alt checker | Pasted HTML | Missing and empty alt attributes. Review descriptive accuracy yourself; the tool does not crawl a website. |
| Check JSON-LD structureJSON-LD structure checker | Pasted JSON-LD | Syntax and common structural fields. Use Google's Rich Results Test for supported search features. |
| Compare a backlink reportCompetitor backlink analyzer | A CSV export from your provider | Local report analysis. It does not discover new backlinks or check whether a link is still live. |
| Compare listed domainsCatalogue Domain Rating lookup | Domain names | Owner-supplied marketplace scores. Missing domains have no result; scores are not live Ahrefs measurements. |
What does SEO stand for?
SEO means search engine optimization: helping search engines understand your content and helping people find useful pages. A tool can assist with a defined task, such as checking text or markup. Its output still needs context, editorial judgment and a check against the page visitors actually see.
Which tools help check SEO content?
Start with the word counter for length, then use the keyword density checker to spot repetition. Check image descriptions and JSON-LD separately when preparing a page. These checks complement a manual review of sources, accuracy and audience fit; they do not produce an overall SEO quality score.
Can I check a site's traffic here?
You can compare supplied traffic estimates for listed publications in the guest posting directory. This catalogue does not measure current traffic for arbitrary websites. For a site you manage, use its analytics for visits and Search Console for Google Search clicks and impressions.
Can I check backlinks or Domain Authority here?
The backlink analyzer works with a CSV you supply, and the Domain Rating lookup uses marketplace records. Neither retrieves a live backlink index or a new Domain Authority score. Read the DA and DR comparison guide before comparing publisher-supplied scores.