Khan Academy is a website offering thousands of free educational videos on a lot of different subjects: Mathematics, Science, History, Economics, Astronomy, Art history and a lot more! The Wikipedia article of Khan Academy give details information on what it is exactly.
The videos are available on their website where you can (optionally) log in, this will give you some features like tracking what you have watched, commenting, asking questions to other people and doing tests and when you pass them very succesfully, the website will optimally show you new videos instead of showing you videos that you do not need to watch because you have understood a specific subject very well. When you use their website, the team behind Khan Academy also track what you are doing so they can improve their website. There is no doubt that by using their website you can learn faster than if you download all the videos on your computer.
However, for various reasons it might be best to download all the videos on your computer. People who do not have access to the internet is one of the main reason. For this, you can download the videos and bring them to people that has no internet connection.
How to download the videos
Download a torrent software, many are available. If you do not know what bittorrent is, first read the Torrents 101: How Torrent Downloading Works article. One torrent software that is free and open source is Deluge. Available for Windows, OS X and Linux. Install it, open it, click on File > Add Torrent > File and select the torrent file that is posted at the top of this page.
Information on the torrent
The torrent is available at all times. It is extremely well organized with descriptive titles. All the videos are in WEBM format which can be played on every operating system, it’s an open format with good quality that doesn’t take much space compared to other video format. We recommend using the free and open source VLC Media Player to play them.
Here’s a preview of some of the videos and how they are organized.
./Arts and humanities/04 - Art history/07 - Baroque to Neoclassical art in Europe - 02 - Rococo/01 - Rococo - 01 - Antoine Watteau,Pilgrimage to Cythera.webm ./Arts and humanities/04 - Art history/10 - Expressionism to Pop Art - 04 - Art between the wars_ the avant-garde and the rise of totalitarianism/02 - The international avant-garde - 02 - Modigliani, Young Woman in a Shirt.webm ./Economics and finance/01 - Microeconomics - 01 - Supply, demand, and market equilibrium/04 - Market equilibrium - 02 - Changes in market equilibrium.webm ./Math by grade/10 - High school/01 - Mathematics I - 02 - Units of measurement in modeling/04 - Word problems with multiple units - 01 - Multiple units word problem_ road trip.webm ./Math by grade/10 - High school/05 - High school geometry - 05 - Right triangles and trigonometry/05 - Solving for a side in a right triangle using the trigonometric ratios - 02 - Solving for a side in right triangles wi.webm ./Math by grade/10 - High school/06 - Algebra II - 01 - Manipulating functions/03 - Shifting functions - 01 - Shifting functions.webm ./Science & engineering/03 - AP Physics 2 - 02 - Thermodynamics/03 - Laws of thermodynamics - 13 - Reconciling thermodynamic and state definitions of entropy.webm ./Science & engineering/06 - AP Chemistry - 04 - Electronic structure of atoms/02 - Bohr's model of the hydrogen atom - 05 - Bohr model energy levels (derivation using physics).webm ./Science & engineering/07 - Organic chemistry - 10 - Aldehydes and ketones/01 - Introduction to aldehydes and ketones - 03 - Nomenclature of aldehydes and ketones.webm ./Science & engineering/09 - AP Biology - 24 - Ecology/07 - Biogeochemical cycles - 07 - Eutrophication and dead zones.webm ./Science & engineering/10 - Health and medicine - 18 - Infectious diseases/01 - Tuberculosis - 07 - Extrapulmonary TB (Part 2).webm ./Test prep/05 - NCLEX-RN - 16 - Nervous system physiology/03 - Neuronal synapses - 04 - Types of neurotransmitter receptors.webm
2017-07-17 Total of 10807 videos, 109920 MBs, 648 hours 2015-07-29 Total of 11136 videos, 119067 MBs, 1301 hours 2015-01-25 Total of 10136 videos, 107613 MBs, 1181 hours 2014-01-25 Total of 6694 videos, 63081 MBs, 817 hours 2013-05-08 Total of 4567 videos, 44351 MBs, 627 hours 2013-01-29 Total of 3883 videos, 38257 MBs, 549 hours 2012-03-28 Total of 3029 videos, 51030 MBs, 466 hours 2011-10-27 Total of 2683 videos, 44760 MBs, 414 hours 2011-08-09 Total of 2523 videos, 41575 MBs, 392 hours 2011-05-06 Total of 2062 videos, 17198 MBs, 325 hours 2010-12-10 Total of 1732 videos, 29708 MBs, 292 hours 2010-10-28 Total of 1618 videos, 26484 MBs, 273 hours
How do I only download specific videos?
One of the most useful feature with torrents is that you can download just what you need. Every torrent software has this option. In Deluge, click on your torrent and look at the Files tab at the bottom, you can right-click on folders and select “Do not download”.
When will a new torrent file be released with new videos?
There is no release dates. This torrent is voluntary work so it happens only when we find the time to make a new one. It usually happens once a year.
A new torrent is out, can I download it over the old torrent I had so as to save bandwidth?
Khan Academy regularly change the structure, folder names and filenames so it is better to delete everything and start downloading the new torrent.
Why is some filenames of video cut-off?
Windows filesystem, unfortunately, has a limit of around 255 characters for the complete path with the filename. So we have implemented a limit of 230 characters for the path and the filename of each videos. The remaining 25 characters is left for the path that the user will download the torrent (i.e. C:\Users\name\Downloads).
How do subtitles work exactly?
A subtitle file, which has an extension .srt, is just a text file containing all the subtitles of a video. To be able to use it, the subtitle file must have the exact same filename as the video and be in the same folder as the video. By just opening the video with VLC Media Player, it will automatically read the subtitle file.
To copy the subtitles files in the same folder as the videos, unzip the Subtitles.zip file just copy all the folders of your language into the folder video so as to merge them. It will place all the subtitles files in the right folder. Note that there isn’t subtitles files for every video. Unfortunately, not all videos are translated.