About

What's an ePub file?

ePub file is one of the file format of eBooks.
eBooks are the electronic form of Books, which are accessed and read in Computers, Mobile Devices, eReaders, Tablets and can be Stored Digitally.
eBooks can be of different formats like epub, azw, kfx, Mobi, prc, lit, pdb, ibooks, etc.,
Among them, ePub file (.ePub) format is the prominent one, being developed and accessed largely by the online users.
ePub files are developed from various file types like text, Html, XHTML, Doc files, by following the basic rules, set by IDPF (International Digital Publishing Forum). They may include Texts, Images and other multimedia contents, confirming to the IDPF Rules.
Apart from the IDPF rules, ePub files has no proprietary Standard, which makes it an Open Standard Format, and so it’s more versatile and largely customizable, more than any other formats of the ePub.
ePub file format, with its varied favorable features, gets supported by almost all devices related to the eBooks for its reading. The devices like Kindle, Nook, iPad, any other Android Tablets, all supports the ePub file format.Validation is a Process, by which any Product or Service would be tested to identify the loopholes and errors, which may hinder the intended outcome of the Product or service. ePub Validation also does the same.
Despite the fact that ePub is an Open Standard Format file, the obligation of catering the diverse demands of the eReaders, Publishers in the market, requires it to have a basic Standard which meets the requirement of all.
What does this ePub Validation Tool Validates? It validates the International Digital Book Forum (IDPF) Rules. By validating these rules and clearing the errors and loopholes, the ePub file is certified to be a valid one, to publish across the online sites, and it can be accessed on almost all eReaders devices.
Furthermore, the ePub contents can be protected on its copyrights by enabling the DRM Rules or can be left open by not including the DRM Rules.
As eBooks are pushing its way in to the Print publishing Books market, so is ePub file formats are to dominate the eBooks formats in near future.

What is ePub Validation?

Validation is a Process, by which any Product or Service would be tested to identify the loopholes and errors, which may hinder the intended outcome of the Product or service. ePub Validation also does the same.

Despite the fact that ePub is an Open Standard Format file, the obligation of catering the diverse demands of the eReaders, Publishers in the market, requires it to have a basic Standard which meets the requirement of all.

What does this ePub Validation Tool Validates? It validates the International Digital Book Forum (IDPF) Rules. By validating these rules and clearing the errors and loopholes, the ePub file is certified to be a valid one, to publish across the online sites, and it can be accessed on almost all eReaders devices.

The Validation checks happening on the files would

    Valid EPUB file structure
    Valid XML code
    Missing or broken files
    Missing of broken links
    Manifest Details
    Navigation plans
    Content Elements and Attributes
    Spine and Guide elements
    Accessibility Issues (More Detail – hyper link)
    And other Technical Details.

Do the Validation! Get the Error-free ePub!!

Why validating .ePub file is necessary...?

ePub file is originally a package. A set of files packed together in one or more folder and organized in a particular order, with metadata identity to each folder and files.
What are all the contents of the ePub file package....

    The original contents in the form of a HTML file,
    The Style Document in the form a CSS file
    The Images in their own format of Jpeg or Giff files
    Other Media files, if any in their proprietary formats,
    A Package file, which has the code of linking all of these files in to one
    A Metadata file, having the Prime identifier for the eReaders,
    There are Spine and Guides, to support different kind of eReaders.

The development or generation of the ePub file is primarily to bundle these files together, in the order and standard set by the IDPF Standard.
As you can see the core of the epub or eBook is the Content. Content of the Book, which may be in any of the format, like Text format, Doc Format, HTML, XHTML ,XML and many others formats.
So it involves lot of conversion work, from one format to another, involving lot of software tools and Macros. And there are times, these would involve manual intervention and involvement also.

The Process of Epub generation would be
Raw Content ---> HTML Document --> Check and View the HTML files --> Do the Error Correction of get the intended view and output --> and do the Packaging.
Since involves lot of process, and considerable amount of manual work, it is highly necessary to check the files through ePub Validation tool.

This Tool is developed based on the Standard of the IDPF, and anything against will be thrown as error, and we have the chance of correcting the same before uploading it online.
Without the Validation, the file will not be a valid one, and can have adverse effect on different eReaders. Hence Validating the ePub file............. Is absolutely necessary.

About epubValidation.com & why we need to prefer the epubValidaiton.com

Ever since the Validation criteria has been set for the eBooks, more particularly the ePub files, lot of ePub validators have emerged and are abundant in the online forum. Each of those sites offer the validation in varied extent, with not so similar results and multiple limitations. The limitations of those Validators may range from limitations on the file size, languages and sometimes the eReaders Devices.

There are even editors, which are used to develop ePub Packages has inbuilt Epub Validators. Eg. Sigil, Calibre etc.

However, We here at epubValidation.com, a pioneer in the Epub Domain for more than two decades, has gone through all of those sites and their limitations, analyzed them, and has come up with this Validator Site, where, we offer the following advantages...

  1. No Restriction on the File Size.
    Since we are Operating through the Cloud, we have no restrictions on the size of the files. We can process files of large size with ease than the other sites.

  2. No Local download of files.
    The Entire operation of the Validations is programmed to be executed from the cloud, and so the files are completely safe and will be erased from cloud once the validation errors are thrown.

  3. ePub Preflight Checking is Included, which would check the following conditions of whether, Content files that are empty.
    Content files that are over 300KB, [which might have issues with some of the eReaders.] Image files that are empty.
    Image files that are over 10MB

  4. Apple and Kindle Compliance Validation
    Specific Checks on the compatibility for the Apple eReaders, and Kindle Devices will be checked.

  5. Other Languages Checks are to be included.
    We are on the way to process and validate the Non-English language ePubs.

  6. Accessibility Conditions are checked.
    The Recent Validation of Accessibility, — a process check for the ePubs for being ready to be accessed by those having visual disabilities, hearing impairments, and other cognitive Reading issues — will also be checked.

  7. We do the Validations for the ePub2 Version and ePub3 Version based on the Metadata itself.


We are a committed to work on these validations regularly, and would be updating the tools and validators more frequently, to have latest updated Validation requirements of any ePub is being fulfilled.