Commons:Maximum file size
The maximum file size on Commons is set at 100 MB (104.857.600 bytes). This is mainly because of technical issues.[1][2] However, users who enable the experimental "Chunked uploads" setting in their user preferences benefit from a limit of 500 MB (524.288.000 bytes) - see Commons:Chunked uploads.[3] Technically it is possible to upload even larger files using server-side upload (see #Help).
This means that it is not possible to upload a file larger than the maximum file size without first breaking it into smaller parts, and uploading those parts as separate files. The template {{Split file}} can be used to link the parts of files split in this way.
Please note that every effort should be made to keep files under the file size limit without splitting them. There are various means to do this, including changing file formats, removing parts of a file not really needed, and downsampling resolution, increasing compression levels, etc. Only where these measures aren't enough (because further loss of detail would reduce quality too much) should files be split.
Maximum size for thumbnails [edit]
In addition to the general size restriction, for several filetypes the software only produces thumbnails and previews on the main file description page below a certain size limit (currently, 50 megapixels[4]).[5] These are PNG, TIF, and GIF. For files where the software does not provide thumbnails because of this limitation, a thumbnail version (either a full-sized JPEG or a smaller PNG) should be uploaded for thumbnail/preview purposes, and linked with the main file. The templates {{Archival version}} and {{Compressed version}} are available for this.
An unrelated reason thumbnails may fail to display (example) is for very long filenames - so long, that they approach the 255-byte limit of filename length (which for some cases with non-ASCII characters may be much less than 255 characters, due to UTF-8). Because thumbnails have additional text added to the name to indicate the width of the thumbnail, this can in some cases take the title of the thumbnail over the 255-byte limit, which means the system cannot handle it. In such cases, renaming the file to a slightly shorter length will solve the problem.[6]
Technical notes [edit]
- ↑ Village pump (2011-11)
- ↑ Wikitech-l (2010-07)
- ↑ http://osdir.com/ml/general/2012-05/msg08815.html
- ↑ The limit was 12.5 megapixels, or about 3500 x 3500, before Bugzilla: 41125 raised the limit in October 2012. The generally limitation is under Bugzilla: 9497.
- ↑ This is because these filetypes can only be thumbnailed by MediaWiki's ImageMagick library by first decompressing the entire image in RAM, which can cause severe server loads. https://lists.wikimedia.org/pipermail/wikitech-l/2005-October/019681.html
- ↑ Bugzilla: 30202
Help [edit]
- Help:Converting video
- Commons:File types#Size and scaling (still image formats)
- Commons:Help Desk
- Help:Server-side upload
