Tanzil - تنزيل

Tanzil Project

Tanzil is a Quranic project launched in 2007 to produce a highly verified Unicode Quran text to be used in Quranic websites and applications. Our mission in the Tanzil project is to produce a standard Unicode Quran text and serve as a reliable source for this standard text on the web.

Why Tanzil?

Since the appearance of the first digital copy of the holy Quran, there had been substantial effort to produce an accurate Quran text, but due to some difficulties (some of which are listed below), these efforts were unsuccessful in many of the cases, and unfortunately, the Quran texts appeared in a majority of Quranic websites and applications were suffering from lots of errors and typos.

[ Google search result for aya 68:38, as of late 2007.] These erroneous Quran texts were so rapidly spread over the Internet that finding the correct form of Quranic verses had became almost impossible without referring to a verified printed manuscript. For example, when we were searching Google in 2007 for the verse 38 of Sura Al-Qalam which is إِنَّ لَكُمْ فِيهِ لَمَا تَخَيَّرُونَ, the first result that we were receiving was a wrong form ending with the word يَتَخَيَّرُونَ as shown in the picture to the right.

This terrible situation made us to launch the Tanzil project to produce a highly verified error-free Quran text, and make this text available to the Quranic websites and applications to prevent further spreading of the erroneous Quran texts.

Typos in some existing texts

Many of the digital Quran texts publicly available on the web have been suffering from lots of typos, mainly due to the following facts:

Missing Diacritics

A popular Quran text which was widely used in websites and applications was based on an old diacritic-less copy of the Quran into which diacritics had been added manually over time by volunteers. Unfortunately, the diacritics added to that text were incomplete and had tons of typos.

Text Conversion

While printed copies of the holy Quran are usually published in Uthmani script, electronic copies of the Quran were commonly prepared in the simple (Imlaei) script. The conversion between these two types of texts had been the source of many inconsistencies and typos in the digital texts.

Technical Limitations

Old Arabic character sets used in Quranic web-pages and applications lacked some essential diacritics and symbols. For example, the widely used Arabic encoding called “Windows-1256” had no code-point for small-alef, which was needed to represent a complete Quran text.

Some instances of typos in existing digital copies of Quran are listed here and here. Some other typos and missing diacritics are listed here.

How precise is Tanzil Quran text?

In the Tanzil project, we have integrated several previous works done in a number of Quranic projects to obtain a unified Quran text, and brought the text to a high level of accuracy by passing it through several manual and automatic verification phases. The lengthy work that lead to the final Tanzil Quran text is summarized in the following three steps:

Automatic Text Extraction

At this step, a collection of Quran texts from several authentic resources was collected, and a program was developed to convert each text to a canonical format. The canonical texts were then analyzed and carefully compared to extract a core Quran text.

Rule-Based Verification

In this step, a program was developed to verify the core Quran text against a set of grammatical and recitation rules. The program was also able to produce Quran texts in Imlaei and Uthmani formats, all derived automatically from the core text.

Manual Verification

In this step, the Quran text produced was examined thoroughly against Medina Mushaf, and a checksum for each letter and diacritic was calculated to verify the accuracy of the text.

We extensively used the help of a group of experts including Quran specialists and Hafizes in order to assure the correctness and preciseness of the obtained Quran text. Our Quran text is now used in major Quranic websites and projects, with several millions active users per month. Despite this high volume of users, we have received no typo report since the release of the first version of the text in 2008. The accuracy of the text has been also reconfirmed by several projects that are actively using Tanzil Quran text.