Most of the time the quote will be based on the number of source words. However, occasionally a translator may charge by the number of target words if the two are likely to be very different (for example Japanese into English). The Project Manager or Translator will be able to advise you.
If you are translating a website or image file, it helps if you can provide the copy in Word format to make sure that nothing gets missed. Translators can also then disregard words that are duplicated on every page (headers and footers for example).
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