This work reports the first electrochemical bioplatform developed for the multidetection of 5-methylcytosine (5-mC) and 5-hydroxymethylcytosine (5-hmC) in DNA, DNA N6-methyladenine (6mA) and RNA N6-methyladenosine (m6A) methylations at global level. Direct competitive immunoassays were implemented on the surface of magnetic beads (MBs) and optimized for the single amperometric determination of different targets varying in length, sequence and number of methylations on screen-printed carbon electrodes. After evaluating the sensitivity and selectivity of such determinations and the confirmation of no cross-reactivity, a multiplexed disposable platform allowing the simultaneous determination of the mentioned four methylation events in only 45 min has been prepared. The multiplexed bioplatform was successfully applied to the determination of m6A in cellular total RNA and of 5-mC, 5-hmC and 6mA in genomic DNA extracted from tissues. The developed bioplatform showed its usefulness to discriminate the aggressiveness of cancerous cells and between healthy and tumor tissues of colorectal cancer patients. First electrochemical bioplatform developed for the multidetection of 5-methyl-cytosine (5-mC) and 5-hydroxymethyl-cytosine (5-hmC) in DNA, N-6-methyladenosine in DNA (6 mA) and RNA (m6A) methylations at global level. Display omitted •First multiplexed bioplatform for global detection of 5-mC, 5-hmC, 6 mA and m6A.•Competitive immunoassays implemented on MBs and amperometric detection at disposable electrodes.•Sensitive and selective multiplexed determination in only 45 min.•Analysis of cellular total RNA and genomic DNA extracted from tumor tissues.•Discriminate the aggressiveness of cancer cells and tumor tissues of cancer patients.