I’ve been using the FPDF PDF generator library for years now as the de facto method for my PHP projects to produce PDF reports. However, one minor annoyance is that the generated PDF files often falter when it comes to the inclusion of certain special characters – like the degree symbol (°) as an example.  (Basically, something like °C becomes °C in the final document)

The reason for this happening is that Arial, the default used/included font, is of type ISO-8859-1 while the degree symbol is UTF-8 encoded. So in order for us to include special symbols or characters from other languages, we need to either try and convert them into our font compatible ISO-8859-1 format, or perhaps switch to using a different TrueType or Type1 font (which then would contain the desired character set).

Now while UTF-8 support is available via a modified class, the easiest way to fix the degree symbol issue without having doing any real work is to simply make use of the PHP utf8_decode function, which convert UTF-8 encoded strings to their ISO-8859-1 equivalents.

In other words outputting utf8_decode(“°C”) to your PDF should result in the expected °C

Related Link: FPDF PDF Generator Library