# Generate a simple digits captcha image **URL:** \ **Category:** Help & Support\ **Created:** [June 12, 2025, 10:55am UTC](https://forum.crystal-lang.org/t/generate-a-simple-digits-captcha-image/8148 "2025-06-12T10:55:30Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![zw963](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.crystal-lang.org/zw963/32/1623_2.png) [@zw963](https://forum.crystal-lang.org/u/zw963)\ **Post date:** [June 12, 2025, 10:55am UTC](https://forum.crystal-lang.org/t/generate-a-simple-digits-captcha-image/8148/1 "2025-06-12T10:55:30Z")
There are some generate PNG shards. but i don’t know how to make image with text in it. > [@PNG implementation in Crystal](https://forum.crystal-lang.org/t/png-implementation-in-crystal/6652): > > Hi everyone, I wanted to share my PNG implementation in crystal: [GitHub - SleepingInsomniac/png: PNG implementation in Crystal](https://github.com/SleepingInsomniac/png). I started working on it to support another project since I didn’t see an existing project with support for all the bit depths, color types, paletted images etc… It was a pretty fun learning experience, and I’m wondering what others think. I found some example code in [pixie](https://github.com/watzon/pixie) shards works for what i need, but the example code not work on my Arch Linux, check [this](https://github.com/watzon/pixie/issues/2) issue. Right now, I just want to make a small, simple picture with some numbers on it. It will be used as a simple check when people sign up on my website. Thanks. ---
**Author:** ![ralsina](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.crystal-lang.org/ralsina/32/2139_2.png) [@ralsina](https://forum.crystal-lang.org/u/ralsina)\ **Post date:** [June 12, 2025, 12:15pm UTC](https://forum.crystal-lang.org/t/generate-a-simple-digits-captcha-image/8148/2 "2025-06-12T12:15:30Z")
This file has code doing it. If you want I can do a more minimal example. > ---
**Author:** ![zw963](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.crystal-lang.org/zw963/32/1623_2.png) [@zw963](https://forum.crystal-lang.org/u/zw963)\ **Post date:** [June 12, 2025, 1:11pm UTC](https://forum.crystal-lang.org/t/generate-a-simple-digits-captcha-image/8148/3 "2025-06-12T13:11:57Z")
Thanks a lot, will be check later. I found another working solution, which use crystal-vips. > ![4560f5ede927992c21343aff21d3c440](https://canada1.discourse-cdn.com/flex036/uploads/crystal_lang/original/2X/6/64881eb287006b674dcfb6135695f395c4f5d92b.png) ---
**Author:** ![zw963](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.crystal-lang.org/zw963/32/1623_2.png) [@zw963](https://forum.crystal-lang.org/u/zw963)\ **Post date:** [June 12, 2025, 5:20pm UTC](https://forum.crystal-lang.org/t/generate-a-simple-digits-captcha-image/8148/4 "2025-06-12T17:20:38Z")
Create a `captcha` shard use [naqvis/crystal-vips](https://github.com/naqvis/crystal-vips/blob/main/example/captcha_generator.cr) > **[GitHub - crystal-china/captcha: Crystal library that generates image CAPTCHAs.](https://github.com/crystal-china/captcha)** > > Crystal library that generates image CAPTCHAs. All credits goes to [the example code in crystal-vips](https://github.com/naqvis/crystal-vips/blob/0f4d3914985865a020168b0f48ece07416eeb459/example/captcha_generator.cr) by @naqvis ---
**Author:** ![syeopite](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.crystal-lang.org/syeopite/32/1420_2.png) [@syeopite](https://forum.crystal-lang.org/u/syeopite)\ **Post date:** [June 12, 2025, 6:37pm UTC](https://forum.crystal-lang.org/t/generate-a-simple-digits-captcha-image/8148/5 "2025-06-12T18:37:53Z")
I don’t think this will be viable for a text-based captcha implementation but for the general case where the images looks relatively the same you could get away with just creating SVGs and then converting to a PNG. The clock captchas that Invidious uses during registrations are generated this way by manipulating SVG attributes on each picture: > ---
**Author:** ![zw963](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.crystal-lang.org/zw963/32/1623_2.png) [@zw963](https://forum.crystal-lang.org/u/zw963)\ **Post date:** [June 15, 2025, 6:26am UTC](https://forum.crystal-lang.org/t/generate-a-simple-digits-captcha-image/8148/6 "2025-06-15T06:26:14Z")
> [@zw963](#): > > Create a `captcha` shard use [naqvis/crystal-vips](https://github.com/naqvis/crystal-vips/blob/main/example/captcha_generator.cr) There is a sister shard, name [simple\_captcha](https://github.com/crystal-china/simple_captcha) All credits goes to @Sunrise The different is: - SimpleCaptcha has no external dependencies other than Crystal，so, you can built static binary (if this is your’s need) - this shard captcha code only support number. These two libraries should be interchangeable without the need to change you code. ![image](https://canada1.discourse-cdn.com/flex036/uploads/crystal_lang/original/2X/0/04d9cc078cb8ba4a0addce2e0a44141268e61b70.png)