I get a real kick out of hunting down legitimate places to read adult manga without the sketchy pop-ups and sketchier morals, so here's what I actually use and tell friends. First off, the safest route is to stick to platforms that pay or at least cooperate with creators. 'Fakku' is the obvious one — it has licensed adult manga, a free section of preview chapters and older volumes that occasionally rotate into
free reads. It also offers subscription access to a larger catalog; even the free bits are clean, well-formatted, and respect creators. Another legit place I check is 'Pixiv' — a ton of artists post doujinshi or short works there, and you can filter for R-18 content once you've verified your age. The quality varies, but it's direct from artists and often free.
If you're okay with samples rather than whole books, 'DLsite' and 'Booth' are great: many creators put up preview pages or freebie works, especially around events or holidays. Following artists on their social media (some still post short works on 'Twitter' or link to free downloads) is a surprisingly pleasant way to find free content and support the people who make it. Avoiding pirated scanlation sites not only helps creators, it also keeps you away from intrusive ads, malware, and sketchy downloads.
On the safety side, I always keep an up-to-date browser, enable an ad/tracker blocker like uBlock Origin, and use HTTPS-only mode; a good antivirus and a privacy-minded browser profile make a big difference. If something asks you to download random executables, close the tab. Supporting creators when you can — buying a volume, subscribing to a service, or tipping on platforms like 'Pixiv' and 'Patreon' — keeps more stuff free for everyone long-term. Personally, I prefer discovering new short works on 'Pixiv' and then buying the ones I love on 'DLsite' or 'Fakku' when I can, and that mix keeps my library both ethical and satisfying.