What are some techniques for reducing a MapInfo TAB's file size without losing too much integrity? The file needs to be reduced for use, not sharing (i.e. zipping).

  • "reduced for use" ... Can you elaborate a bit more on this? Is the size of the table close to 2 GB? Is the width of each row close to 4 KB (with the later versions 64KB)? Are you having performance issues? We need a bit more information in order to give you some useful advice Commented Jul 3, 2015 at 6:58

2 Answers 2


Depending what you mean by "integrity", there are a couple of things you could consider:

  1. Generalise the vector component to reduce the number of nodes - there is a tool HERE which you could use. Or you could try converting the file into Esri Shape (using Universal Translator) and using the generalisation approaches in mapshaper and translate back into Tab afterwards.
  2. Have a look to see if there are any redundant fields in the data - is there attribute data that isn't needed?

To expand on the first point made by Andrew Tice - MapInfo has an object thinning function to remove nodes within a certain tolerance of each other. You can access it through Objects > Snap/Thin... to generalise your vector data.

In addition to removing any redundant data fields, you may want to also look at field types. For example, character fields have an upper size limit of 254 characters, can you reduce the size of any of these? What about changing Integer fields to SmallInt (values must be within -32,768 - 32,767 for a SmallInt, any larger or smaller and you'll have to stick with Integer)? Careful consideration of the minimum required table structure could save you quite a bit of disk space in the resulting files.

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