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LibreTexts - Free The Textbook
LibreTexts is developing the next generation of open-access texts. Open. Free. Accessible to all.
https://libretexts.org/
2 high issues
6.1%
3 medium issues
9.1%
4 low issues
12.1%
24 tests passed
72.7%
0.09 seconds
7.31 kB
27 resources
Secure
Seo
Title
The title tag is perfect.
LibreTexts - Free The Textbook
Meta description
The meta description tag is good.
LibreTexts is developing the next generation of open-access texts. Open. Free. Accessible to all.
Headings
Only one h1 tag should be present on the webpage.
  1. What else can LibreTexts do?
  2. Join our growing community
  1. The World's Most PopularOnline Textbook Platform
  2. Join more than 30 million Online Learners
  3. Check out our other exciting advanced features!
  1. 398
  2. 154
  3. 223 million
  4. $31 million
  5. Click here to see more
  1. Knowledge at your fingertips
  2. Ready to hit the books?
  3. OPEN
  4. COMPREHENSIVE
  5. TOPICAL
  6. COMMUNITY
  7. INTERACTIVE
  8. ACCESSIBLE
  1. STUDENTS
  2. INSTRUCTORS
  3. INSTITUTIONS
  4. VOLUNTEERS
  5. Everything my students need
  6. Sophisticated and customizable
  1. Dr. Jessica Coppola, Professor of Nutrition and Gerontology at Sacramento City College
  2. Dr. Marc T. Facciotti, Professor of Biomedical Engineering at the University of California, Davis
Content keywords
The content has relevant keywords.
libretextsfreethetextbook
Image keywords
There are 16 images with missing alt attributes.
  1. https://libretexts.org/img/LibreTexts/glyphs_blue/bio.png
  2. https://libretexts.org/img/LibreTexts/glyphs_blue/biz.png
  3. https://libretexts.org/img/LibreTexts/glyphs_blue/chem.png
  4. https://libretexts.org/img/LibreTexts/glyphs_blue/eng.png
  5. https://libretexts.org/img/LibreTexts/glyphs_blue/espanol.png
  6. https://libretexts.org/img/LibreTexts/glyphs_blue/geo.png
  7. https://libretexts.org/img/LibreTexts/glyphs_blue/human.png
  8. https://libretexts.org/img/LibreTexts/glyphs_blue/k12.png
  9. https://libretexts.org/img/LibreTexts/glyphs_blue/math.png
  10. https://libretexts.org/img/LibreTexts/glyphs_blue/med.png
  11. https://libretexts.org/img/LibreTexts/glyphs_blue/phys.png
  12. https://libretexts.org/img/LibreTexts/glyphs_blue/socialsci.png
  13. https://libretexts.org/img/LibreTexts/glyphs_blue/stats.png
  14. https://libretexts.org/img/LibreTexts/glyphs_blue/workforce.png
  15. https://libretexts.org/img/testimonials/Jessica_Coppola.jpg
  16. https://libretexts.org/img/testimonials/Marc_Facciotti.jpg
SEO friendly URL
The URL is SEO friendly.
https://libretexts.org/
404 page
The website has 404 error pages.
https://libretexts.org/404-6901ed8ccf8fd66c74c5688a1bece452
Robots.txt
The webpage can be accessed by search engines.
Noindex
The webpage does not have a noindex tag set.
In-page links
The number of links on the webpage is okay.
Language
The webpage has the language declared.
en
Favicon
The webpage has a favicon.
https://libretexts.org/img/favicons/favicon.ico
Performance
Text compression
The HTML file is compressed.
Load time
The webpage loaded in 0.09 seconds.
Page size
The size of the HTML webpage is 7,312.00.
HTTP requests
There are fewer than 27 HTTP requests on the webpage.
  1. https://www.googletagmanager.com/gtag/js?id=UA-109132099-1
  2. https://cdnjs.cloudflare.com/ajax/libs/jquery/3.4.1/jquery.min.js
  3. https://awesomefiles.libretexts.org/Molecules/GLmol/js/Three49custom.js
  4. https://awesomefiles.libretexts.org/Molecules/GLmol/js/GLmol.js
  5. https://awesomefiles.libretexts.org/Molecules/GLmol/js/GLWrapper.js
  6. https://libretexts.org/js/jquery/jquery-2.2.4.min.js
  7. https://libretexts.org/js/bootstrap/popper.min.js
  8. https://libretexts.org/js/bootstrap/bootstrap.min.js
  9. https://libretexts.org/js/plugins/plugins.js
  10. https://libretexts.org/js/active.js
  1. https://libretexts.org/style.css
  2. https://libretexts.org/css/index.css
  1. https://libretexts.org/img/LibreTexts/glyphs_blue/bio.png
  2. https://libretexts.org/img/LibreTexts/glyphs_blue/biz.png
  3. https://libretexts.org/img/LibreTexts/glyphs_blue/chem.png
  4. https://libretexts.org/img/LibreTexts/glyphs_blue/eng.png
  5. https://libretexts.org/img/LibreTexts/glyphs_blue/espanol.png
  6. https://libretexts.org/img/LibreTexts/glyphs_blue/geo.png
  7. https://libretexts.org/img/LibreTexts/glyphs_blue/human.png
  8. https://libretexts.org/img/LibreTexts/glyphs_blue/k12.png
  9. https://libretexts.org/img/LibreTexts/glyphs_blue/math.png
  10. https://libretexts.org/img/LibreTexts/glyphs_blue/med.png
  11. https://libretexts.org/img/LibreTexts/glyphs_blue/phys.png
  12. https://libretexts.org/img/LibreTexts/glyphs_blue/socialsci.png
  13. https://libretexts.org/img/LibreTexts/glyphs_blue/stats.png
  14. https://libretexts.org/img/LibreTexts/glyphs_blue/workforce.png
  15. https://libretexts.org/img/sponsors/UCD.png
Image format
There are 25 images that are not using the AVIF, WebP format.
  1. https://libretexts.org/img/LibreTexts/glyphs_blue/bio.png
  2. https://libretexts.org/img/LibreTexts/glyphs_blue/biz.png
  3. https://libretexts.org/img/LibreTexts/glyphs_blue/chem.png
  4. https://libretexts.org/img/LibreTexts/glyphs_blue/eng.png
  5. https://libretexts.org/img/LibreTexts/glyphs_blue/espanol.png
  6. https://libretexts.org/img/LibreTexts/glyphs_blue/geo.png
  7. https://libretexts.org/img/LibreTexts/glyphs_blue/human.png
  8. https://libretexts.org/img/LibreTexts/glyphs_blue/k12.png
  9. https://libretexts.org/img/LibreTexts/glyphs_blue/math.png
  10. https://libretexts.org/img/LibreTexts/glyphs_blue/med.png
  11. https://libretexts.org/img/LibreTexts/glyphs_blue/phys.png
  12. https://libretexts.org/img/LibreTexts/glyphs_blue/socialsci.png
  13. https://libretexts.org/img/LibreTexts/glyphs_blue/stats.png
  14. https://libretexts.org/img/LibreTexts/glyphs_blue/workforce.png
  15. https://libretexts.org/img/LibreTexts/header_logo_mini.png
  16. https://libretexts.org/img/LibreTexts/header_text.png
  17. https://libretexts.org/img/testimonials/Jessica_Coppola.jpg
  18. https://libretexts.org/img/testimonials/Marc_Facciotti.jpg
  19. https://libretexts.org/img/sponsors/CSU_ALS.png
  20. https://libretexts.org/img/sponsors/DOE.png
  21. https://libretexts.org/img/sponsors/UCD.png
  22. https://libretexts.org/img/sponsors/Merlot.png
  23. https://libretexts.org/img/sponsors/NSF.png
  24. https://libretexts.org/img/sponsors/UCD_Library.png
  25. https://libretexts.org/img/LibreTexts/header_logo.png
JavaScript defer
The are 6 javascript resources without the defer attribute.
  1. https://www.googletagmanager.com/gtag/js?id=UA-109132099-1
  2. https://libretexts.org/js/jquery/jquery-2.2.4.min.js
  3. https://libretexts.org/js/bootstrap/popper.min.js
  4. https://libretexts.org/js/bootstrap/bootstrap.min.js
  5. https://libretexts.org/js/plugins/plugins.js
  6. https://libretexts.org/js/active.js
DOM size
The DOM size is optimal.
The HTML file has 313 DOM nodes.
Security
HTTPS encryption
The webpage uses HTTPS encryption.
The HTML file has https://libretexts.org/ DOM nodes.
Mixed content
There are no mixed content resources on the webpage.
Server signature
The webpage has a public server signature.
GitHub.com
Unsafe cross-origin links
The webpage does not have unsafe cross-origin links.
Plaintext email
The webpage does not contain any plaintext emails.
Miscellaneous
Structured data
There are no structured data tags on the webpage.
Meta viewport
The webpage has a meta viewport tag set.
width=device-width, initial-scale=1, shrink-to-fit=no
Character set
The webpage has a charset value set.
UTF-8
Sitemap
No sitemaps found.
Social
The webpage has 2 social links.
Content length
The are less than 500 words on the webpage.
The webpage has 456 words.
Text to HTML ratio
The text to HTML ratio is 10%.
Inline CSS
The webpage contains inline CSS code.
  1. position: absolute
  2. background-image: url(img/bg-img/compressed/bg_1920_study_group.jpg);
  3. padding: 10%
  4. background-image: url(img/bg-img/compressed/bg_1920_study_laptop.jpg);
  5. padding: 10%
  6. background-color: #127bc4; height: 3px; width: 85%;
  7. background-color: #127bc4; height: 3px; width: 85%;
  8. display: flex; align-items: center; flex-direction: column
  9. text-align: center
  10. font-size: larger; font-weight: bold; color: #127BC4;
  11. color: #127bc4
  12. overflow-wrap: break-word
  13. background-color: #127bc4; height: 3px; width: 85%;
  14. display: flex; align-items: center; flex-direction: column; margin-bottom: 20px
  15. text-align: center
  16. font-size: larger; font-weight: bold; color: #127BC4;
  17. display: flex; align-items: center; flex-direction: column; margin-bottom: 40px
  18. font-size: larger; font-weight: bold; color: #127BC4; display: flex; justify-content: center; flex-wrap: wrap
  19. color: dodgerblue; white-space:nowrap; padding:5px;
  20. color: green; white-space:nowrap; padding:5px;
  21. color: orange; white-space:nowrap; padding:5px;
  22. background-image: url(img/bg-img/compressed/bg_1920_math.jpg);
  23. padding: 10px
  24. padding: 10px;
  25. color: #606060
Deprecated HTML
There are no deprecated HTML tags on the webpage.