Hark vs Sider: which one should you use?
Sider is a polished sidebar for reading, writing and comparing answers from several AI models. Hark is a sidebar that also does things on the page. If you need an agent, that difference is everything.
Choose Sider if you want to compare answers from many models, translate PDFs and summarize videos. Choose Hark if you want the assistant to carry out tasks on websites, draft email replies into your reply box and keep track of orders and deadlines.
At a glance
Hark and Sider, side by side.
| Hark | Sider | |
|---|---|---|
| What it is | Chrome extension — an AI agent in the side panel | Multi-model AI sidebar for reading and writing |
| Where it runs | Google Chrome on Windows, macOS, Linux and ChromeOS | Browser extensions and apps |
| Acts on websites | Yes — clicks, types and fills forms in your current tab | No agent described — text and reading tools |
| Approval before final steps | Always, before send, submit, book, pay or delete | Not applicable |
| Email help | Summaries, reply drafts and deadlines in Gmail & Outlook on the web | Writing and rewrite help |
| Tracker for orders & deadlines | Built-in Tracker for orders, bookings, bills and deadlines | No |
| Account needed | No account — install and use | Account required |
| Free plan | 1 AI request per day, all modes | About 30 basic credits a day |
| Paid plans | $5.99/week (2-day trial), $14.99/month or $39.99/year | From about $8.30/month billed annually; higher tiers cost more |
| AI models | OpenAI models, in Fast and Smart modes | GPT, Claude, Gemini, Grok, DeepSeek and others |
Choose Hark if…
- You want tasks completed, not only answered
- You want replies inserted into Gmail or Outlook
- You want a tracker for what you are waiting on
- You want to start without an account
Choose Sider if…
- You want group chat across several models
- You translate PDFs or watch a lot of video
- You want a mature reading and writing toolkit
Reading tools vs doing tools
Sider is built for the reading-and-writing half of knowledge work: side-by-side model answers, PDF translation that keeps the layout, video summaries with bilingual subtitles. Hark covers the basics of that half — page summaries and questions — and puts its effort into the other half: the clicking, typing, booking and following up.
Do you need many models?
Model choice is Sider’s headline feature. Hark gives you two settings, Fast and Smart, and chooses the models behind them. If you enjoy comparing models, Sider wins. If you just want the task done, two settings are plenty.
FAQ
Hark vs Sider: common questions
Can Sider fill in forms or book things?
Sider focuses on chat, reading and writing tools. We found no agent that completes tasks on websites in its public feature list at the time of writing.
Is Sider free?
Sider has a free tier with a small daily allowance and paid plans. Check Sider’s site for current pricing.
Can I use Hark and Sider together?
Yes. They are separate extensions.
More comparisons
Hand your next task to Hark.
Add it to Chrome, open the side panel and say what you need. It takes about ten seconds.
Free plan included · No account needed · Works in Chrome on Windows, Mac, Linux and ChromeOS