Computer-based spell checkers help to correct misspells instantly. Almost all the word processing devices are now equipped with a spell-check function that either automatically corrects errors or provides a list of intended words. However, it is not clear on how the reliance on this convenient technological solution affects spelling learning. According to cognitive load theory convenience might be harmful for learning because it reduces the amount of effort invested in the learning task. In this study, effects of spelling aids on detecting and correcting misspelled words were examined by comparing English as a second language students' performances on detecting and correcting the misspelled word across four conditions: control, red underline, spell-check (drop-down list), and dictionary. Learning transferability and durability were also examined. Results indicated that all spelling aids induced error-detection learning even when the errors were presented in a different context (transferability) or in a delayed posttest (durability). For error-correction learning, results showed that both the spell-checker (drop-down list) and the dictionary helped the students to learn the spelling incidentally. On the delayed posttest, error-correction performance in these two aided conditions was significantly higher than the performance in the control group. In conclusion, effort spent on searching for the correct words relates to better incidental spelling learning. Convenience and effort should be considered as factors influencing incidental spelling learning in the design of computer-based spell checkers.