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Show HN: I built a tool to help you read Hacker News on Kindle (ktool.io)
393 points by longnguyen on Aug 29, 2022 | hide | past | favorite | 78 comments
Hi HN, I'm Daniel Nguyen. In June, I quit my job to start indie hacking full-time.

The idea of KTool first came to my mind when I was reading "Ask HN: I'm a software engineer going blind, how should I prepare?"[0]

I've been wearing glasses since I was 5. My right eye is basically blind. Doctors said there is no chance to cure it.

I was genuinely scared. Like holy shit, if my left eye stops working, my life is done. Since then I've been very conscious about time spent on computer screens.

That's when I started using Kindle-related products: to offload as many reading materials as possible to the Kindle. I was a happy customer of Push to Kindle. Great product!

Then I ran into multiple limitations which led me to build KTool: a tool to send anything online to Kindle. Blog posts, Twitter threads, Hacker News discussions, RSS, newsletters... you name it.

But I'm not here to pitch my vision for KTool.

I built a specific tool to help you send HN discussions to your Kindle. And in the spirit of Show HN, it doesn't require an account. If you don't own a Kindle, there is the option to download the EPUB.

Let me know what you think. Any feedback will be much appreciated.

If you're a Kindle owner and you read a lot of online content, give KTool a try.

[0]: https://news.ycombinator.com/item?id=22918980




Hi Daniel,

Congratulations on the launch!

I received an email from HN user telling me about this post because a while back I was running 'HN to Kindle' service[0] and since Amazon enabled 2FA for bulk emails even for approved email ids I lost motivation to run it further and instead made the core application open-source[1].

Since you're sending HN item individually, I'm not sure whether you'll face the 2FA block but do monitor whether your users are getting your emails delivered by connecting with them.

Your website's presentation is way better than mine, Perhaps because you've put JS to good use. Feel free to use my code to implement other features like classification according to chosen topics if you'd like it.

[0] https://web.archive.org/web/20220216140431/https://hntokindl...

[1] https://github.com/abishekmuthian/hntoebook


Thank you for your work!

Yeah I haven't run into the 2FA issue yet, but probably will. Is there any docs about this 2FA issue I can read (other than the short doc on amazon.com)?

Thanks,


Amazon enabled 2FA after an attack vector with vulnerabilities was demonstrated using email delivery[1] on Kindle. The researcher says that Amazon now(Jan 2021) sends verification link if they cannot authenticate the email id.

But my hntokindle.com email id had SPF & DKIM from the start and the verification links started occurring only late last year (or) early this year. That's what lead me to believe that the 2FA is enabled after the number of emails from an email id crosses a threshold.

I don't expect Amazon to clarify this in their docs. They might have whitelisted domains from known services like Instapaper (I think they generate unique sender email ids) along with the id they use for 'Send To Kindle' if they used email for that in the first place.

Although it might be possible to reverse engineer 'Send To Kindle' browser extension to send your HN item, But it might also raise legal issues(INAL).

[1] https://medium.com/realmodelabs/kindledrip-from-your-kindles...


Hi Daniel

First, I love what you've done here, and why - congratulations on making it this far!

A few suggestions:

1) An independent web route is important, but you could lower the friction even further with browser plugins. Like you, for general articles I use push-to-kindle[0] which only needs two clicks - no copy/paste, etc.

2) Have you also thought about including a copy of the original article - so that in a single download, there's the article followed by the HN discussion, all accessible from the document's index?

3) I could see this developing further as a productivity tool via subscription - maybe I set up an account with you and then receive a digest of the day's top-10 (or 20, whatever) articles and discussions. Or a weekly digest? Might be a powerful way to divert people away from the regular distraction of HN, but still allow consumption.

Good luck :)

[0] https://www.fivefilters.org/push-to-kindle/


Thanks for your valuable feedback.

1. I've actually developed that[0]. Using the browser extension is even more powerful as it could send content behind paywalls to Kindle — something not possible for the web UI.

The reason I didn't mention it is it requires an account, probably not a good thing for a Show HN.

2. Yes. I'm not sure if that's a useful feature, but personally, I don't like it. I want the original article to be a separate ebook so highlights & notes go into the correct entry. But that's an interesting feature for sure. Probably will make it a user preference.

3. Yes! That's 100% on my road map. And not just for HN. I got beta support for newsletters now but it doesn't work with a digest-type newsletter.

Thank you again!

[0]: https://ktool.io/install


I would definitely be interested in receiving the day's top-10 (or 20, whatever) articles and discussions.


> 1. I've actually developed that[0]. Using the browser extension is even more powerful as it could send content behind paywalls to Kindle — something not possible for the web UI.

Ah, I see it now when I load your full site, rather than the HN-specific page. Great to know!


I'm in a similar situation as as you in that I wear glasses and have busted right eye due to eye muscle surgery in the early 1980s. I can "see" out of it but reading text is impossible unless it's like a foot tall. The thought of avoiding screens never occurred to me. Wouldn't any medium be it a screen, paper book, or Kindle cause eye strain on your left eye? I've seen many optometrists/ophthalmologists over the years and nobody recommended to avoid screens. One doctor advised me to avoid using contacts since eyeglasses always give you eye protection for the left eye and that was it.


Oh, I didn't know that using contacts is not advisable. Thank you. Between doing a LASIK and using contacts, I was leaning toward the latter. But now probably will just wear glasses.

I find computer screens cause more eye strain than Kindle.

Yeah, I don't think we can avoid screens completely. I just wanted to offload some of the reading to the Kindle. So I could read outside more.


Definitely don't do LASIK. Look into the rates of complications and side effects. There's a good argument that it's really not a procedure that should have ever been approved.

I don't think the advice to avoid contacts as a baseline recommendation is the takeaway of the comment you replied to, that advice pertained to that person's specific medical situation.

Also, personally, I don't believe it's the type of screen that's problematic for long-term eyesight. What my optometrist told me is that we weren't really evolved to be looking at things close up for long periods of time.

I don't think e-ink versus backlit screen is the issue – certainly, our eyes take in a lot more ambient light from not-screens during the day compared to the weak little LED light on our screen.

The real issue is spending 8+ hours a day focused on close up objects. Take frequent breaks where you are looking in the distance, go on walks, etc.

Remember to listen to your doctor over random people on the Internet, including me.


> Definitely don't do LASIK. Look into the rates of complications and side effects. There's a good argument that it's really not a procedure that should have ever been approved.

Can you provide more details on this? A cursory search doesn't turn up anything especially alarming. The only source I could find that was alarming is this[0], which I don't really trust because it reads a bit like anti-vax literature ("see what they're hiding", etc.) and is very old (all sources they cite are from 2009 or earlier). My understanding has been that the procedure has improved dramatically in that time in both cost and safety.

[0] https://lasikcomplications.com/


Perhaps I'm not as well-informed on this subject as I thought, because I had done some research months/years ago but I'm not really finding solid information reporting on the dangers as was the case with you.

One of the big ones I had found was risk of chronic dry eyes being really high, but that seems to be with PRK surgery and not LASIK. Rates of long-term dry eyes after 12 months for LASIK appears to be 0.8% according to the papers I found, which you could argue is pretty low.

I wouldn't discount the idea that modern practices and equipment works a lot better. A lot of the horror stories I do find are older, like you mentioned.


AFAIK, the way LASIK works is by cutting down part of the lens, which essentially is to reshape the eye to compensate for the elongated eye ball. Given it's an invasive surgery, personally I'm not too comfortable. A friend of mine also shared that his girlfriend can't no longer drive at night after having a LASIK surgery due to the glare and halo effect.

A year ago I came across Todd Becker's method to cure myopia here from HN as well. In case interested to check it out: https://www.youtube.com/watch?v=x5Efg42-Qn0

There's also a PDF from a different guy with some practical guide. Feel free to email me at denny at nusantara-cloud.com if you want me to share it.


> Perhaps I'm not as well-informed on this subject as I thought, because I had done some research months/years ago but I'm not really finding solid information reporting on the dangers as was the case with you.

Would you mind going back and adding that in your original post, as you've got pretty big unsubstantiated claims about LASIK.


1. You can't edit posts after a short time

2. I still haven't changed my general opinion about LASIK: it seems too much like a "convenience surgery" to me, i.e., most people who get it have correctable vision with eyeglasses/contacts. It's also not hard to find stories from the minority of people who had complications and regret it.

3. My original comment came with this disclaimer: "Remember to listen to your doctor over random people on the Internet, including me."


From last I read PKR was a better choice if you have the time for it to heal because it removes far less material and doesn't form a flap which is a physical weak point that hard physical activity or a poke in the eye can dislodge.

But with PKR you also have wait like up to a month before vision is clear again, versus lasik giving mostly clear vision within like a day or so. So with PKR long term it is less physically vulnerable but it puts your vision out of commission for a week or two atleast.


https://www.cbsnews.com/pittsburgh/news/lasik-eye-surgery-co...

Is I believe the original


https://www.youtube.com/watch?v=x5Efg42-Qn0

Are you aware of Todd Becker's method to reduce myopia? I've been doing it in the past 1 year and am happy to report that I've had 1.5 reduction in my glasses prescription (from 6.75). There's a PDF from a different person with a concrete guide on how much to reduce. I can share it if you're interested, feel free to email me at denny at nusantara-cloud.com :)


I love the idea, and would consider paying for this after a nice trial period. I love my kindle and it has radically changed how much I read, I used to read maybe 2-3 books a year, now it's more like 2-3 books a month. I find the E-ink screen and "low techness" of it the most appealing. I'm really looking forward to using this for things other than books.


I was skeptical of screen readers until the Kindle e-ink. Have some OLED or LCD screen that you find on the standard tablets like some of the original Barnes and Nobles Nooks was just not appealing or comfortable. e-ink screens have definitely been a value on on my personal appeal on them, especially the Kindle's backlit ones.


Thanks for making this. This type of software makes e-ink much more usable.

I also suggest trying Android e-ink readers from companies such as Hisense or Onyx Boox as they've come a long way in the last few years. (Not affiliated with them, just a bit obsessive on the topic)

With the upcoming generation of color e-ink and large companies starting to notice (Apple, Huawei) it's only going to get better and better moving forward.


> Onyx Boox

No way I’m going to support company like that.

https://www.reddit.com/r/Onyx_Boox/comments/hsn7kx/onyx_usin...


Onyx has had problems complying with the GPL in the past. Have they fixed that?


I'd be surprised if they ever will. For my part, I just use afwall and other related services and accept the risk.


> my vision for KTool

I see what you did there.

Didn't Amazon tighten up how custom content is delivered to Kindles fairly recently, requiring 2FA? So you need to connect the Kindle to load the content?


Haha, the pun wasn't intended.

So far I haven't run into the 2FA issue yet. I made sure the email configuration was correct (all those SPF, DKIM, DMARC kinds of stuff) and the KTool email was added to their Approved email address list.


I don't think so. Not too long ago I was able to send an EPUB to my Kindle by sending it to a kindle email address from an "approved" sender.

Here's the help article describing that process: https://www.amazon.com/gp/help/customer/display.html/?nodeId...


I just signed up for a year to try it out. A few things: 1) The way you get the kindle email address is slick, but some people might get squicked out from a privacy standpoint because you are scraping information from a logged in Amazon account. Perhaps present an obvious option for the user to input the kindle email address. 2) There is no share functionality with the iOS app - I understand that there is an extension in safari itself, but I should be able to pass the app via the share button - this is how all these kind of services do this (P2K, Share to Kindle, Evernote, Joplin, Dropbox, Day One - etc.) You are the first service to use a safari extension to share webpages that I have come across. The upside of using the share functionality, is that any browser can access your service - not just safari users. 3) Cleaning up documents on the Kindle is a PIA. Consider bundling - or giving the option to bundle them into a "book". Maybe two options - add to my periodic (weekly/daily) "book" and another option to send an article immediately. 4) Most people are not going to spend 50 bucks for an annual subscription to try something out for a bit - consider offering monthly subscriptions. Hope this helps!


Wow that's a GREAT feedback. Thank you a lot. Please find my answers below:

1) You are right. I build KTool with privacy in mind and I've thought about this. There is always the option to set it up manually[0][1] but probably it wasn't obvious. I'm open to any UX suggestion here.

I should mention that the KTool extension doesn't require any special permission, unlike Instapaper which asking to access your webpages _all the time_[2]. KTool cannot access the web pages you visit until you click on the extension icon and perform an action.

2) Yeah and the instructions for the iOS extension is not even clear. I developed it for some of my paying customers and haven't paid much attention yet. Thanks for the feedback.

PS: don't listen to the Internet. The new Web Extension is not better than building a Share Extension.

3) Great idea. Will implement that next.

4) There is always the monthly subscription option[2] and this UI/UX is pretty common among SaaS. I'm not sure how can I make it more obvious. Again, any UX suggestion is welcome.

[0]: https://share.cleanshot.com/AOk1Ii

[1]: https://share.cleanshot.com/wLrjRh

[2]: https://twitter.com/daniel_nguyenx/status/155730594021050368...

[3]: https://share.cleanshot.com/sqrUzZ


I use Amazon's official extension to send webpages to Kindle all the time. [1]

My feedback: I can't justify paying $4/month to be able to send few packaged webpages to my kindle, If this was a one time payment of ~$20, I'd be interested.

[1]. https://chrome.google.com/webstore/detail/send-to-kindle-for...


Thanks for your feedback and I'm glad that the official extension works well for you. All I can say is you probably are not my target customers.

Most of the time, the official extension doesn't work for me. And I'm not alone. You can check their recent reviews[0]. A lot of 1 star.

I'm aware that there are other alternatives such as Push to Kindle, P2K, Instapaper, newslettertokindle etc. They provide much better conversion quality than the official extension, and better deliverability. I'm confident that KTool is on par with them, maybe better in some use cases (such as Twitter threads, HN, sending pdfs...). And their paid plans range from $2.99/mo to $10/mo.

What I'm doing at KTool is to support all those content in a single subscription.

I hate subscriptions, but until we found a better model, I can't sell it as one time payment. My expense is recurring (CPU for parsing & image processing, email + bandwidth to send articles to Kindle, Apple developer program, core parser maintenance as sites structure changes...)

But I will definitely do more experiment with pricing though.

Again, thanks for your valuable feedback. Much appreciated

https://chrome.google.com/webstore/detail/send-to-kindle-for...


I have to say, your setup process for your chrome extension is very slick. I look forward to giving this thing a shot, I use Pocket to save articles but it's kind of just a junk drawer for me, and I'd prefer to force myself to read from my Kindle anyway vs my iPad so I don't get distracted easily.


The blurred-out notice makes it seem like some form of scam. I would rework the site to present the entire process to potential sign-ups on first glance.


I never thought of it. Thank you!


Do you have a way for me to demo the RSS support? I'd love to have a calm technology flow for reading articles on my kindle and I think ktool may just be what I'm looking for.


Currently, KTool doesn't support RSS yet. I will work on RSS next. I do have beta support for newsletter though, if you wanted to read Stratechery or Substack newsletters.


I read lot of blogs, made something similar [0] a while ago. Write now installing it is painful, if you don't have calibre or node js installed. Re-writing it all in nodejs, so that installation is easier. Calibre is not needed now, as amazon started converting epubs to azw3.

[0] https://github.com/nikhil1raghav/kindle-send


As a professional platform builder, I’m always amazed at how good of a piece of hardware Amazon has made, with how limited it’s platform experience is

Kindles can only (easily) do what Amazon wants it to do —full stop.

It’s like the iPhone before the App Store.

I bet Amazon would make a massive amount of money if they opened up their ecosystem to let others develop on top of it


I bet it wouldn't move the needle. Their books/Kindle ratio might even drop. Although I know my Kindle is really a computer, I don't want it to act like one. I want a dedicated and narrowly focused ereader.

If I were head of that division at Amazon, I'd remove bluetooth, APIify the bookstore (so you can buy books from other retailers), remove GoodReads integration, and direct the hardware people to focus on battery life and the software people to focus on layout and typography. I'd also add a physical switch to enable/disable the touchscreen. All Kindles would have physical page turn buttons like the Oasis does.


I think I agree. I'm glad my Kobo doesn't have a Twitter app.

Kobo's Pocket integration is nice, so I can read through articles I've saved on my computer/phone without distraction. There's also an Overdrive store so I can browser and borrow books from my local library without jumping through hoops.

Would it be nice to support alternatives to Overdrive and Pocket? Sure, but once you open the doors to any third-party apps, it's hard to keep the focus on books.


They have done just that with their Android based non-eink Kindle Fire line. They run their own app store and it's not great. Imagine having all the junk of the Play market but with most of the good stuff missing. The only reason I use mine is because it's possible to install the F-Droid and Play apks so you can use it more or less like a regular Android tablet.

I use my regular e-ink kindle 100% offline, I never turn off airplane mode. I only load content via USB using the Calibre CLI. I don't want my Kindle to do cool stuff. I used to think I did, I rooted my early Kindles and tried to do as much on them as possible. But then I realized that it's only a distraction from the one thing the Kindle is actually good at: reading long static text documents.


In fact, they used to allow people to create apps for the Kindle, but they took away that ability later.


I faintly remember a load of bingo and bejeweled clone shovelware circa 2012.


When I saw this I was hoping for something that was more about the articles themselves as well as the main page. Would love to have an e-reader experience in the morning versus use my phone.


That's interesting. I will add that feature next.

Meanwhile, you can sign up for an account and send articles using the main product (the browser extension).


> In June, I quit my job to start indie hacking full-time.

What has that been like?


A lot of self-doubt haha. I got a decent savings so I don't have much financial pressure yet. Also the Twitter indie hacker community is super supportive. That helps a lot.


I like this! I was wondering if this also sends the articles from HN, not just the comments. It'd be game changing to wake up and read the news on my Remarkable.


Thanks. Yes, but you need to sign up for an account to send articles though.


welcome to the monkey house, dan.

combining HN and kindle is intriguing. my most serious work occurs laying in bed reading, before falling asleep. i will surely follow your work.


I’m curious. Do you consider reading your most important work? What’s your occupation?


Nice! i often wished for this before a flight, but it would need to include the article and comments in offline mode =)


Not related, but I came up with a workaround to add scrolling for Kindle on Desktop. Kindle doesn't support scrolling on their desktop app -- they only allow page-by-page reading for some wacky reason. Workaround is to install "Windows Subsystem for Android", then read it on the kindle app inside the subsystem.


Been using this for a few months, really solid replacement for Amazon's own send-to-kindle, with a lot of potential.


Thanks for your continued support!


I was under the impression you can opt to simply download the epub and send it to Kindle yourself but the website will not let me do anything before I set up the Kindle upload.


I love this. This is the killer feature that would get me to buy a kindle. If the affiliate program were still as lucrative as it was I'd use your link to do just that. what a cool thing you've built!


You can get a Kobo instead, it has native Pocket integration.


Any chance to be able to use this on reMarkable? It has epub support


It's on my road map. I got requested support for reMarkable & Kobo but I wanted to build a _really_ good tool for the Kindle first. Stay tuned. Thanks


If you add Kobo support and ship the Android app, you've got a premium member for life in me!

Currently, I use KoboCloud to sync cloud drive (Box, Google Drive, et al.) folders to my readers, one folder for each family member. I use browser extensions to create epubs for websites on the fly and save them to the cloud drives, but can't find a great-looking solution for mobile (Android in particular). Many sites I visit like HN comment sections just don't reformat well and it looks like you have a wonderful solution implemented for that aspect.


Glad to hear that. I will keep that in mind. Thank you.


there's send by mail" functionality in Kobos via Pocket, but it would need you to spoof the sender for attribution ( https://help.getpocket.com/article/1020-saving-to-pocket-via... ) and the account to whitelist the email address prior. My impression towards "pocketed" hn-links is they're crawled once and not refreshed - so you miss out on many comments if the article was already cached when it had only a few comments.


I plan to add integration with dropbox and g.drive to my (similar) tool - Sendtoreader during September. Once that's done, reMarkble will get everything needed to receive web content, including RSS feeds subscriptions (full-text format)


That would be great. I've had formatting issues with Web-to-epub browser extensions so have been usin "Print Friendly" for web-to-pdf on desktop, and Shortcuts print-to-pdf on iOS.


Cool idea! Will it be possible to provide a list of HN articles (eg. the best of the week) to send to Kindle (or ePub)? Thanks!


Very well done, I can't wait to give it a try!


This is neat! I used to do this with modded firmware and an RSS feed of the HN frontpage, it's quite a wonderful experience.


Website says cancel with click of a button...can't find the button...

Can't find an email to try to get a refund.

found in email.


Sorry for the confusion and I'm glad you figured it out. The payment was handled securely by Paddle.com and you can always manage/cancel yours using the link from their email.

If you don't mind, please let me know why you subscribed and then quickly canceled? My email is in profile.

Much appreciated.


Amazing work! Great to see such a tool getting the recognition it strongly deserve. Love it already!


Something like a weekly digest of most popular HN posts in the epub/pdf format would be great.


Just to play devils advocate, I 100% do not want this.

I understand your reasons for making this and I fully support them, but the day Amazon make the Kindle into something other a way to read books is the day I drop the kindle for another reader.

The whole point of a Kindle for me is that I can use it to read and not be distracted by notifications or wondering what's on HN or whatever.


In the spirit of both this app's purpose and your desire for purity on the Kindle, I could see this being a perfect companion to Longreads type sites where I rarely want to read a 25 minute article on my laptop or phone and so frequently skip the article altogether.

Now to decide whether that use case is worth the monthly cost to me.


It was exactly me a couple of years ago. KTool has the free-forever plan that you could send a few articles per month. I believe this fits you perfectly.

TBF, nobody wants to pay 4 bucks a month for 3-4 articles.

But once you developed the habit of reading almost everything on Kindle, I believe 4 bucks/mo doesn't sound very expensive ;-)


Please consider a word application on kindle as your next project.


I may be missing something - but how exactly do I Use it?


I thought the UI was pretty obvious but here is how you can use it[0]

1. You enter a Hacker News story URL (such as this one)

2. Click on Preview. You should see the content rendered on the Kindle mockup

Now you can send it to your Kindle (follow step 3,4,5) or download the EPUB file (6)

3. Enter your send-to-kindle email address. To find yours, follow this guide[1]

4. Make sure you whitelist kindle@ktool.io on your Amazon account settings. Refer to this guide[2]

5. Click "Read on Kindle" and enjoy

[0]: https://share.cleanshot.com/yUODpW

[1]: https://thebookbuff.com/how-to-find-your-kindle-email-addres...

[2]: https://www.amazon.com/gp/help/customer/display.html?nodeId=...




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