This study sought to understand how well students (n = 274; M[subscript age] = 12.45) were able to identify the author, the main claim, and the supporting evidence (identification performance) and to justify the author's expertise, the author's benevolence, and the quality of the evidence (justification performance) while reading multiple online texts. The study also examined the contribution of prior topic knowledge and basic reading skills (word recognition and reading comprehension) to students' identification and justification performance. Students read two more and two less credible online texts about sugar effects on health. After reading each text, they responded to multiple-choice items that measured the identification and justification performance. Justifying credibility seemed more challenging for students than identifying the claim, evidence, and author. Word recognition and reading comprehension were statistically significant predictors of identification performance, whereas prior knowledge and reading comprehension were statistically significant predictors of justification performance. The findings offer new insights into the relationship between basic reading skills and credibility evaluation that can inform both theory and instruction.