# Calibre 107 Hacker News commenters recommended Calibre and 15 criticized it, November 2025 to November 2026. It was recommended in 13 of 13 months; owners who said how long report a median of 10 years (4 owners). It meets the Hacker Approved badge rule. **Verdict:** Free, open-source ebook manager that converts formats and loads books onto Kindles and Kobos, keeping old e-readers useful; its clunky, unfriendly interface is the common complaint. ## Why people recommend it - Converts between ebook formats (8 comments): "Calibre does does the conversion on the fly when I upload my books, so I don't really experience any issues there" ([source](https://news.ycombinator.com/item?id=49094756)) "Calibre can do that with no loss of quality with a checkbox, and page turns are much much faster." ([source](https://news.ycombinator.com/item?id=49512669)) "You can add books using the Calibre software which converts epubs and mobi files I think." ([source](https://news.ycombinator.com/item?id=47749821)) - Easy transfer to e-readers (6 comments): "Being able to just turn on wifi and click "calibre" > "connect" to transfer books from my PC is a killer feature" ([source](https://news.ycombinator.com/item?id=49104915)) "USB+calibre is my only option as I do not wish to share my reading habits with the zillionaire overlord" ([source](https://news.ycombinator.com/item?id=49512692)) "I can just get the Ebook or PDF files and transfer them via Calibre, simple as that" ([source](https://news.ycombinator.com/item?id=47692059)) - Keeps old Kindles usable (3 comments): "Calibre lets you put non-Amazon eBooks on these very same devices. It made me start using my old Kindle again" ([source](https://news.ycombinator.com/item?id=47748399)) "If not for Calibre, I would have absolutely no option of ever getting new books on it." ([source](https://news.ycombinator.com/item?id=49512020)) "Calibre still speaks the format of these old Kindles, so they're usable" ([source](https://news.ycombinator.com/item?id=47838086)) - Organizes whole ebook library (4 comments): "every PDF I download, ebook, academic article, it goes in Calibre and out of my Downloads path." ([source](https://news.ycombinator.com/item?id=47056820)) "I went and converted the entirety of my library to Calibre with multiple open formats." ([source](https://news.ycombinator.com/item?id=48255829)) "ebooks mean you can search highlights, categorize them, see summaries of them" ([source](https://news.ycombinator.com/item?id=48886477)) ## What people warn about - Ugly, unfriendly interface (6 comments): "I use it weekly, but by the gods, it's neither pretty nor friendly." ([source](https://news.ycombinator.com/item?id=46180901)) "it's weirdly shoddy software, slow as a dog, and the worst UX i've ever seen in a popular app" ([source](https://news.ycombinator.com/item?id=47839171)) "making Calibre's UI less unpleasant before adding yet another bolted-on AI chat textbox" ([source](https://news.ycombinator.com/item?id=46178112)) - Hard for beginners (2 comments): "I like Calibre, but it is not great for people who are just getting started." ([source](https://news.ycombinator.com/item?id=46464489)) "Calibre is simplest but probably not for completely non-technical people" ([source](https://news.ycombinator.com/item?id=49837702)) - Unwanted AI chat feature (2 comments): "Does Calibre really need its own AI chatbox when I can ask the same question to ChatGPT in a browser?" ([source](https://news.ycombinator.com/item?id=46393539)) "making Calibre's UI less unpleasant before adding yet another bolted-on AI chat textbox" ([source](https://news.ycombinator.com/item?id=46178112)) - Heavy and slow (2 comments): "you can write an app like Calibre in Python and QT and it is much lighter" ([source](https://news.ycombinator.com/item?id=48356509)) "it's weirdly shoddy software, slow as a dog, and the worst UX i've ever seen in a popular app" ([source](https://news.ycombinator.com/item?id=47839171)) ## Alternatives hackers recommend - [Calibre-Web](https://hackerapproved.com/p/calibre-web.md): 19 recommend - [Grimmory](https://hackerapproved.com/p/grimmory.md): 9 recommend - [Kavita](https://hackerapproved.com/p/kavita.md): 5 recommend - [Send to Kindle](https://hackerapproved.com/p/send-to-kindle.md): 5 recommend - [Shelfmark](https://hackerapproved.com/p/shelfmark.md): 5 recommend ## Cite as Hacker Approved, "Calibre", https://hackerapproved.com/p/calibre/ (counts from 1,795,640 Hacker News comments, November 2025 to November 2026).