MangaDex is one of the largest manga scanlation websites that offers users the opportunity to freely access and read manga online. It allows scanlation groups to upload and share their work. Therefore, it's well-known for providing a wide range of manga titles in multiple languages with high-quality translations.

MangaDex has a vast collection of manga titles, including popular series, lesser-known works, and fan translations. It covers a wide range of genres, from action, romance to crime and mystery, so you're sure can find your favorite stuff here.

It supports manga series in multiple languages. While the library is mostly available in English, you can find manga translated into over 20 languages, making it accessible to readers from various regions. MangaDex allows scanlation groups to upload and share their work, making it accessible to a wider audience.

In addition to offering high-quality manga translations, MangaDex is a legal, ad-free platform with high-quality comic images. This is why it's considered one of the best websites for reading action manga.

Pros:

• Professional translations with high-quality images
• User-friendly interface with multiple sorting options for easy navigation
• Ad-free experience
• Ability to customize reading preferences and bookmark your favorite manga
  

Cons:

• Update time is not fixed because it depends on fan translations

Website: https://mangadex.org/

WEBTOON is a popular digital platform that offers a wide range of webcomics, comics, and manga. Besides famous titles, WEBTOON also publishes a wealth of original creations with a variety of genres, including many action-themed manga.

For fans who want to enjoy their favorite series as soon as possible, you should try its Fast Pass service. This is WEBTOON's subscription service allows users to access the most recently published episodes before their official release. You must use Coins to use this feature by depositing money into your WEBTOON account or hunting for Free Coins through promotional events.

However, even without Fast Pass, you can enjoy unlimited free manga reading on WEBTOON. The platform provides a user-friendly reading experience with its mobile app and website. Readers can explore, rate, and comment on comics, allowing for a vibrant community and easy discovery of new and trending series. Moreover, WEBTOON frequently holds contests for authors, which means its users can enjoy featured works on its platform, that are hard to find on other sites.

In summary, WEBTOON has grown in popularity around the world, and it is still a popular platform for manga book fans looking for a digital and interactive reading experience.

Pros:

• A wide range of webcomics, comics, and manga for free
• Allow reading before the official release date
• Offer translations

Cons:

• Lack of originality in some manga
  

Website: https://www.webtoons.com/

MANGA Plus is a prominent online platform for manga enthusiasts founded by Shueisha, one of the largest publishing companies in Japan. It offers a diverse and extensive collection of manga titles from various genres, making it a go-to destination for manga readers of all tastes. This site offers an official and legal way to experience manga content, benefiting both producers and readers.

With a focus on offering a wide range of manga, including popular action and crime titles, MANGA Plus has become a favorite among manga fans worldwide. Through MANGA Plus, you not only have access to popular and high-rated manga but also without any cost because all of its library is free for everyone! However, Japan, China, and South Korea are not included in this service.

As SHUEISHA's official website, MANGA Plus also delivers new chapters of popular manga on the same day they are released in Japan. Additionally, users can participate in conversations with readers from worldwide and even engage in interviews with the authors regarding their works on the website.

Pros:

• Completely free
• A wide range of popular action manga
• Many languages available
• User-friendly web interface

Cons:

• The availability of manga depends on the country/region due to licensing restrictions

Website: https://mangaplus.shueisha.co.jp/

Another popular manga reader site that shouldn't be missed is VIZ Manga, the official platform operated by VIZ Media. Recognizing the potential of manga, VIZ Media was among the first to bring English versions of manga to Western audiences. Over the years, it has grown into one of the largest graphic novel publishers in the United States, focusing on translating contemporary titles for worldwide readers.

VIZ Manga offers a diverse range of manga series through its online platform. Readers can enjoy a mix of free content, including previews and the latest chapters, as well as opt for a paid subscription for just $2.99/month, granting them full access to an extensive library of over 100 titles. This collection spans classics like "Death Note", "One Piece", "Naruto", and "Pluto: Urasawa x Tezuka" together with newer works such as "Demon Slayer" and "My Hero Academia".

Moreover, you can read the latest manga chapters on VIZ Manga as they are released in Japan. For action manga enthusiasts searching for a premium and legal platform to indulge in their favorite genre, VIZ Manga is one of the best choices with its vast selection, regular updates, and user-friendly interface.

Pros:

• Large library with manga from VIZ media and many big publishers
• Officially licensed manga titles
• Affordable subscription fee
• Free content

Cons:

• The website version has fewer features compared to the app version

Website: https://www.viz.com/read

BookWalker is an eBook store launched by KADOKAWA and is an excellent website for reading action manga. It provides a vast collection of manga titles from various publishers such as KADOKAWA, Kodansha, Shueisha, and Shogakukan, including many action series. You'll find both classic and new action manga series to enjoy.

The manga available on BookWalker is official and of high quality. You can expect high-quality images and professional translations for an immersive reading experience.

When you purchase manga on BookWalker, it becomes a permanent part of your collection. You can re-read your favorite action manga anytime you like. Moreover, BookWalker offers a membership ranking system that rewards users with coins for their purchases. Higher rankings earn you more coins, which can be used for future manga purchases.

BookWalker has two subscription plans, including unlimited reading of manga, magazines and of paperbacks, light novels. A cost-effective way to explore new manga titles without a full subscription is the "free every day" feature, which allows users to access one volume of selected work for free every 23 hours after completing the initial fee

So, if you're a fan of action-packed manga and appreciate the convenience of a legal, user-friendly platform, BookWalker is an excellent choice to explore and enjoy your favorite action manga titles.

Pros:

• A vast selection of manga and light novels from various publishers
• EBook deals and free previews of manga chapters
  

Cons:

• Most manga require payment
  

Website: https://global.bookwalker.jp/