WriterPi vs Sider — an honest comparison
Sider is one of the most established AI sidebar extensions for Chrome. WriterPi is the newer challenger. Here's how they actually stack up in 2026, from someone who built one of them and has used both for months.
Full disclosure: I built WriterPi. I have tried to write this comparison fairly and call out where Sider is genuinely stronger. You will decide if I succeeded — you can also flip to their website and check my claims.
The quick verdict
Both tools do broadly the same job — an AI sidebar in your browser that reads pages and helps you write. Sider is the older, more polished product with more features. WriterPi is newer, cleaner, cheaper, and focused on the writing use case specifically.
Pick Sider if you want the most mature product and don't mind paying a bit more. Pick WriterPi if you want a fair price, a clean interface, and something built by a solo founder who actually replies to emails.
Feature by feature
| Feature | WriterPi | Sider |
|---|---|---|
| Reads the page you're on | Yes, one-toggle | Yes |
| Free tier | 10 msgs no signup, 25/mo signed in | Limited daily quota |
| Cheapest paid plan | $1 for 3 days | $8-10/mo starting |
| Mid-tier plan | $6/mo (500 msgs) | $10-20/mo (varies) |
| Writing tones | 8 (incl. Gen Z) | Basic tone options |
| Themes | 3 (Dark, Green, Galaxy) | Light/Dark only |
| Image scanning | Yes | Yes |
| Chat history sync | Local session only | Cross-device sync |
| Team features | No | Yes (Business tier) |
| Data used to train AI? | No, never | Check their policy |
| Founder replies to email? | Yes, personally | Support team |
Where Sider wins
Cross-device chat history
Sider syncs your chat history across Chrome, mobile browsers, and their desktop app. WriterPi does not — chat lives in the current browser session. If you're the kind of person who wants to pick up a conversation on your phone, Sider wins here.
Feature breadth
Sider bundles a lot: image generation, PDF chat, ChatPDF-style document uploads, translation, coding help, note-taking, an art generator. It's a Swiss Army knife. WriterPi is deliberately narrower — writing, replies, summaries, and page reading. If you want everything under one roof, Sider is the more complete option.
Business / team plans
Sider has real team tiers with SSO and admin controls. WriterPi is single-user only right now. If you need to deploy to 20 employees, Sider is your answer.
Where WriterPi wins
Price
WriterPi starts at $1 for a 3-day pack. Sider's cheapest tier is around $8-10/month. If you use an AI sidebar occasionally but not daily, WriterPi's short-pack pricing means you can spend $1, try it fully, and stop — no monthly commitment. Pro at $6/mo and Max at $9/mo are also below Sider's equivalent tiers.
Interface
Sider has grown a lot of buttons over the years. WriterPi's sidebar is deliberately quiet — one input, a tone selector, a page toggle, chat history. Fewer decisions per message. Personal preference, but it makes a real difference on long writing sessions.
Writing tones
WriterPi has 8 real tones including a Gen Z voice that actually sounds like a person under 25, not a marketing team's guess at one. The tones change the writing meaningfully, not just add a "friendly" label to the same output.
Data policy
WriterPi never trains AI on your conversations, never sells your data, and never stores the pages you ask about on our servers. This is stated in plain English on the privacy page. Sider's policy is longer and less clear on some of these points — worth reading it yourself before choosing.
Founder access
WriterPi is built solo. If you email hello@writerpi.com, the founder replies. Bugs get fixed within days, not quarters. Feature requests actually make the roadmap. Sider is a bigger team and support is fine but it's a team, not a person.
Which should you pick?
Pick Sider if:
- You want the widest feature set (image gen, notes, PDF chat, art)
- You need cross-device chat history sync
- You're deploying to a team or business
- You're happy paying $10-20/month for a mature product
Pick WriterPi if:
- You mainly want writing help + page summaries + email replies
- You want a clean, quiet interface with no feature bloat
- You want to spend $1 to try it fully before any monthly commitment
- You want a real Gen Z / casual writing voice, not just a tone label
- You care about clear, simple data policies
- You'd rather email a founder than a support queue