The most functional tool to help you add an image in a PDF is LightPDF. This is a free online editor which can convert PDF documents to Word, PNG, JPG, PPT, TXT and convert Word, JPG, PNG, PPT and Excel back to a PDF file. Aside from that, there are other functions which you can try out to enhance your content such as signing, merging, splitting, unlocking, protecting, compressing, rotating a PDF and so on. You can directly access and proceed with the editor even without signing up. Simply follow this guide on how you can add an image into a PDF with this tool. First and foremost, visit LightPDF, where you shall click the "PDF to Word" button under the "Convert from PDF". In the box, tap the "Choose file" to add PDF document or simply drag and drop the file into the box to upload. Afterwards, download the Word document and open it. From there, select an image then drag and drop it to the document to add. Once finished, go back to the program's page. Under the Convert to PDF tap "Word to PDF". Upload the Word file where you inserted an image and wait until it is converted. Then click the "Download" icon to save your file. Pros. The tool has a user-friendly interface. The program can instantly edit and convert PDF files online. It is a completely free and reliable tool with no watermark and there is no limitation set on converting and editing files. It can work on different platforms including Windows PC, Mac OS, Android and iOS devices. Cons. It works only with constant internet connection, so you can't use it offline.