Best free video converter: How we tested

Our first measurement of video conversion tool quality comes in looking at its features. How many formats can it import and export, for instance? Do these cover all the options you'll need?

We checked to make sure that you can carry out basic tweaks during the conversion process, like changing the video resolution. And we awarded extra marks for bonus features, such as the ability to edit the source video before converting it.

Video editing can be a complicated, jargon-packed process, so we were also interested in ease of use. We wanted our conversion tools to provide access to low-level conversion options (sometimes that's very useful), but these should never get in your way.

Our utilities should ideally provide sensible default settings at all times, and device presets as well, so you can export to, say, an iPad 2 just by selecting it from a list.

And as converting videos can take a very long time, performance is particularly important. To measure this, we gave each conversion tool four tests.

Starting with the source files from Big Buck Bunny, we converted the 1080p surround-sound AVI to 320x240 WMV; tried transcoding the 480p MOV to MP4 (vital as that's such an important format these days); and converted the 320x180 MP4 file to both FLV and MPEG2.

AVI to WMV

AVI to wmv

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MOV to MP4

MOV to mp4

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MP4 to FLV

MP4 to flv

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MP4 to MPEG2

MP4 to mpeg2

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While these tests don't cover every possibility, they provided a great deal of very useful information. So read on to discover which conversion tools you really need to consider, and the programs you should avoid at all costs.