Updated in May 2017 to include new information and recommendations on the SVG format and software compatibility
For a logo in a Word or Powerpoint document – SVG, GIF or PNG
If you have the latest Office 365 you can use an SVG file, so long as you’ve already got one or have the software to make one. Otherwise, you can use a GIF (.gif) or PNG (.png) file. These are ‘bitmap‘ files (pictures made of dots), and will be easily imported by Office applications. Don’t use JPEG (.jpg) files – they are generally unsuitable for logos – jpgs are intended for colour photographs, and often spoil the fine detail in text. I prefer GIF or PNG files because they use up less disc space, but bigger BMP (.bmp) files are an alternative. You might also be able to use a EMF (enhanced metafile) format, which is a windows-only vector format and so has the advantages of the EPS file I describe below, but may be difficult for beginners to work with. You can make an EMF file with Adobe Illustrator.
In order to place your logo file in Word to make stationery, you’ll need the techniques described here: how to set up stationery in Word.
For a web page SVG, or GIF or PNG
Now that Internet Explorer 8 is hardly used anymore, you can use vector SVG files on your web pages, which are supported in all other browsers and in IE 9 and up. These have the advantage of being infinitely scalable and also tend to be the smallest file sizes. So they are going to look perfectly sharp on ‘retina’ phones and tablets – this is a huge advantage. You could also use a GIF or PNG file. You should get one the right size before you upload it – not too big or you waste people’s time and bandwidth; not too small, because it will look very bad if it has to be scaled up in the browser.
Here the GIF file is all but useless. You need an EPS or PDF file. These are ‘Vector‘ files. Because EPS files are big, I often convert them to PDF which results in a much smaller file which is also less likely to get corrupted when emailed. When I originally wrote this piece, it was still usual to send a Quark document together with the logo EPS to the printer, together with the fonts you used. Now professional designers usually supply a PDF file of the whole job. Although PDF is suitable for holding a single logo file, it can also be used for multipage documents with crops and bleeds and so is perfect for supplying print-ready artwork. Professional graphic designers will also use AI – Adobe Illustrator files, but these are not a format often used for exchanging files.
GIF format logo
Blockyness when enlarging bitmap
Bitmap files are made up of a grid of square dots. When you enlarge them, you can see the dots. If you have a bitmap file, you can’t convert it to a vector file except by tracing it in vector software, either automatically or by hand, whereas vector files can be converted to bitmap without loss of quality. Examples of bitmap file formats are JPG, GIF, PNG, BMP.
EPS Encapsulated Postscript Files are vector files and used by printers, designers and other graphics professionals. Logos designed in Illustrator or Freehand (most are) will be originally in this format. From this file, you can make as many ‘bitmap’ versions at whatever size you choose. They are infinitely scalable.
GIF Graphic Interchange Format. This sort of bitmap file is very good for simple line art, logos and icons. It is rubbish for photos, as it reduces the number of colours creating a characteristic, and usually unwanted ‘speckled’ effect.
GIF format logo
JPEG format logo
PDF Portable Document Format are vector files and used by printers, designers and for general document distribution. They have all the advantages of EPS format and a smaller file size. Take care, though – these files may contain embedded bitmaps which will not scale.
PNG Portable Network Graphics files are bitmap files. The format was invented to replace GIF which has problems with patent requirements. The format supports a wider range of options than GIF and is well supported by web browsers. It should not be used for professional print.
SVG Scalable Vector Graphics are an open web standard for delivering logos and other graphics which will look crisp on any device at any size. These files can only be generated by a vector-based graphics programme like Illustrator and CorelDRAW, rather than a photo editing tool. SVGs were adopted as a web standard in 1999, but slow implementation by Microsoft (it is only properly supported in IE9 and above) delayed their widespread use on the web until the last few years. Now it is safe to use them and they are probably the best format to use online, if you have the software to generate them.
Vector files are made up of mathematically described geometric lines and shapes (rather than coloured dots) and so will never get ‘blocky’, whatever size you print them. Examples of vector formats are SVG, EPS, AI, PDF, EMF.