A few people have asked me about these phrases recently. Do they have the same meaning? When is each one used?
By contrast / In contrast
I often use these two phrases in both writing task 1 and 2. They are exactly the same, and are used in a similar way to "however" or "on the other hand" to introduce a contrast / comparison. Put "By / In contrast" at the beginning of a sentence, with a comma after "contrast".
Unemployment rose in the UK. By contrast, the number of unemployed people in Canada fell.
On the contrary
I've never used this phrase in any of my IELTS lessons. It doesn't mean the same thing as "by / in contrast". We use "on the contrary" to deny that something is true, and to explain that the opposite is true.
- Person 1: "You had some problems with your hotel, didn't you?"
- Person 2: "On the contrary, the hotel was great, but the airline lost my suitcase."