This study argues that ‘assessment for learning’ can bridge the gap between language learning practices and assessment, and address washback effects in testing. Assessment for learning is defined as teaching practices and learning for providing feedback used to improve students performance. Class blogs were offered as a means of instructing and providing lesson activity feedback for six English comprehension classes to support language learning objectives and test-taking goals. Class homepages were set up as blogs, and used by the teacher and students accessed the homepages on their smartphones. The aim of this study was to investigate if blogging provided necessary support and aided in test preparation. Data was collected from i) observations made, ii) student responses from a blog survey, and iii) a comparison of test results which were evaluated using an AI application ‘Cathaven’. These CEFR test results indicated a positive washback affect, and survey blog responses showed that assessment exercises and test preparation conducted using feedback blogs were beneficial and improved test performance. I discuss these findings and give implications associated with an alternative testing and learning ESL context with relevant literature in blogs in education, which reframes blogs in the context of contemporary language education utilizing AI.