i2OCR is a free online Optical Character Recognition (OCR) that extracts text from images so that it can be edited, formatted, indexed, searched, or translated.

Free online OCR service that allows to convert scanned images, faxes, screenshots, PDF documents and ebooks to text, can process 122 languages and supports layout analysis

Best free OCR API, Online OCR and Searchable PDF (Sandwich PDF) Service. Try instantly, no registration required. Available as On-Premise OCR Software, too. The Cloud OCR API is a REST-based Web API to extract text from images and convert scans to searchable PDF. Free OCR software as a hosted service and as download.