The second estimate of gross domestic product (GDP) for April to June put growth at 0.4%, up from the first estimate of 0.3%.
The European statistics agency Eurostat also revised growth in the first quarter, from 0.4% to 0.5%.
Also on Tuesday it was announced that German imports and exports had both reached record levels.
Boosted by the continuing weakness of the euro, exports rose 2.4% to â‚¬103.4bn ($115.5bn; Â£75.1bn) in July, the federal statistics office Destatis estimated, after adjusting for seasonal and calendar effects.
Imports also rose, but not by as much, meaning the trade surplus grew to a record â‚¬25.0bn.
The upward revision to GDP for the first quarter is a result of the inclusion of Ireland, which had not been counted in earlier estimates.
The Irish economy grew 1.4% in the first three months of 2015, compared with the previous quarter, making it the fastest-growing eurozone country.
With the Irish figures not yet included, the fastest-growing eurozone member in the second quarter was Latvia at 1.2%.
Economic growth in the 19 countries that make up the eurozone has been revised upwards.