ProphetProphet vs Sider: AI Sidebar Extensions Compared
Sider gives you many models to chat with. Prophet gives you three Claude models that can click, type and fill forms. Full feature table inside.
Last updated: March 2026
Sider and Prophet are both side panels, and that is roughly where the similarity ends. Sider is a reading and writing companion: it is excellent at taking the page in front of you and doing something textual with it — summarise, rewrite, translate, explain, draft a reply. Its standout feature, group chat, fires one prompt at GPT, Claude and Gemini simultaneously and shows the answers side by side, which is genuinely useful when you do not yet know which model handles a task best. What Sider does not do is act. It can tell you what the form says; it cannot fill it in. Prophet inverts the priorities: one model family, three tiers of it, and 18 tools that click, type, navigate, scroll and manage tabs through the Chrome DevTools Protocol. The practical test is simple. If your sentence ends in "...and summarise it", Sider is the better and cheaper tool. If it ends in "...and then submit it", Sider cannot complete the sentence at all.
Feature Comparison: Prophet vs Sider
A side-by-side breakdown of how Prophet and Sider handle the key capabilities you need from a browser AI extension. This comparison covers page understanding, automation depth, pricing, model selection, and data privacy.
| Feature | Prophet | Sider |
|---|---|---|
| Page Understanding | Accessibility tree snapshots | Page text extraction |
| Speed | Fast - structured data, no vision model | Fast for chat; limited automation speed |
| Pricing Model | Pay-per-use credits | Monthly subscription tiers |
| Starting Price | Free ($0.20 credits included) | Free tier with daily limits, Pro from $10/month |
| Browser Automation | 18 tools (click, fill, navigate, tab management) | Limited - mainly text selection and summarization |
| Models Available | Claude Haiku 4.5, Sonnet 5, Opus 5 | GPT-4, Claude, Gemini, and others |
| Data Privacy | Page content processed locally; messages only to API | Page content sent to multiple third-party AI providers |
| Open Source | Yes - full source on GitHub | No - closed source |
Where Prophet Wins
Prophet's core advantages come from its architectural decisions: the accessibility tree for page understanding, Chrome DevTools Protocol for automation, and a usage-based billing model that aligns cost with value.
Full browser automation with 18 tools that can click, type, navigate, and manage tabs - not just read page text
Pay-per-use pricing so light users save significantly compared to a flat monthly fee
Open source codebase allows inspection of exactly what data is sent and where
Accessibility tree approach provides deterministic element targeting for reliable automation
Where Sider Wins
Sider has legitimate advantages that matter depending on your use case. Here is where it pulls ahead:
Supports GPT-4, Gemini, and Claude in a single extension, giving users model flexibility
Mature product with a large user base, polished UI, and features like AI reading lists and group chat with multiple models
Which Should You Choose?
Choose Prophet if you need an AI that can actually interact with web pages -- clicking buttons, filling forms, navigating between pages, and managing tabs. Prophet's 18 automation tools go far beyond reading and summarizing text. Its pay-per-use pricing also makes it the better choice for users whose AI usage varies month to month. If you value open source transparency and want to verify exactly what data your browser extension collects, Prophet's public GitHub repository gives you that assurance.
Choose Sider if supports GPT-4, Gemini, and Claude in a single extension, giving users model flexibility, and mature product with a large user base, polished UI, and features like AI reading lists and group chat with multiple models. If those specific capabilities are central to your workflow, Sider may be the better fit despite Prophet's automation advantages.
Both tools can be installed side by side in Chrome, so you can test each on your actual workflow before committing. Prophet's free tier includes $0.20 in credits -- enough for dozens of messages to evaluate whether it meets your needs.
Pricing: Prophet vs Sider in practice
Four tiers versus no tier
Sider prices in the normal SaaS way: a capped free tier, then Basic at $8.99/month, Pro at $12.99/month, and Unlimited at $24.99/month, with the better models and higher quotas gated to the upper tiers. The friction point users report most often is that "Unlimited" still meters advanced-model queries, so the top tier does not remove the thing you were paying to remove. Prophet has no tiers in that sense — credits are credits, every model is available at every level including free, and 1 credit is 1 cent of real Anthropic API cost plus a 20% margin. The comparison that matters: Sider Pro costs $155.88 a year whether you use it or not. Prophet at 20-30 Sonnet messages a day runs roughly $12-18 a month, light use runs a couple of dollars, and a month where you forget the extension exists costs exactly nothing. Sider wins on price only if you are a heavy multi-model user who would otherwise be buying two subscriptions.
To price your own usage rather than ours, the AI API cost calculator works from your real message volume, and pay-per-use AI vs subscription pricing explains where the break-even sits. Full tier details are on the Prophet pricing page.
Switching between Prophet and Sider
Sider stores conversations and reading lists in its own account and offers no export, so history does not come with you — most people treat the switch as a clean start rather than a migration. Both extensions can be installed simultaneously, and because Sider is popup-and-sidebar while Prophet is a true Chrome side panel, they do not fight over screen space. The habit that takes longest to unlearn is Sider's selection-first workflow: you highlight text, then choose an action. Prophet is instruction-first — you describe the outcome and Claude decides which of the 18 tools to use. Users switching over typically spend their first week still highlighting things before realising they can just ask.
When Sider is the better choice
You want GPT, Claude and Gemini in one panel, you actively use group chat to compare model outputs, your work is overwhelmingly reading and writing rather than acting on pages, or you want a mature product with a large user base and years of polish. Sider is a better reading companion than Prophet and we would not pretend otherwise — Prophet has no equivalent of its context-adaptive reading tools or its AI reading list.
Prophet vs Sider: common questions
Is Prophet a good Sider alternative?
If you want browser automation, yes — Prophet is the only one of the two that can click buttons, fill forms and navigate pages. If you want multi-model chat and reading tools, Sider remains the stronger product and Prophet is not a like-for-like replacement. Prophet is Claude-only by design.
Does Sider have browser automation?
No. Sider reads page text and acts on selections — summarising, rewriting, translating and drafting. It cannot click elements, fill form fields, navigate between pages or manage tabs. Prophet does all four through 18 Chrome DevTools Protocol tools.
Is Prophet cheaper than Sider?
For light and moderate users, substantially. Sider Basic is $8.99/month and Pro is $12.99/month regardless of usage. Prophet bills pay-per-use credits at Anthropic API cost plus a 20% margin, so typical sidebar usage of 20-30 Sonnet messages a day lands around $12-18/month, light use costs a couple of dollars, and an unused month costs nothing. Heavy daily multi-model users may find Sider Unlimited better value.
Can I use both Sider and Prophet at the same time?
Yes. They are separate Chrome extensions with no conflict, and the pairing is fairly common: Sider for multi-model reading and comparison, Prophet for anything that requires the AI to actually act on the page. Prophet's free tier makes running both cost nothing extra to trial.
Which models does each support?
Sider covers GPT-4, Claude and Gemini, with model access tied to your subscription tier. Prophet is Claude-exclusive but offers all three current tiers — Haiku 4.5, Sonnet 5 and Opus 5 — on every plan including the free one, which is unusual; most extensions reserve frontier models for paid tiers.
Other comparisons and next steps
If you are still narrowing the field, these cover the neighbouring options and the wider category.
- Prophet vs Claude in Chrome — Anthropic's official extension needs Claude Pro at $20/mo and reads pages by screenshot. Prophet reads the accessibility tree and bills per use.
- Prophet vs Monica AI — Monica is a polished multi-model chat sidebar. Prophet is Claude-only but acts on the page. Price, models and automation compared.
- Prophet vs MaxAI — MaxAI is built for one-click actions on highlighted text. Prophet runs multi-step browser tasks. Where each one is worth the money.
- Best AI Chrome extensions in 2026 — nine extensions ranked, including this one, with free tiers and real prices.
- Best Chrome extensions for Claude AI — the Claude-specific ranking if you have already settled on the model.
- Free Claude AI: every free tier and limit — what you can do without paying either product a cent.
Try Prophet Free
Install the extension, get $0.20 in free credits, and see how accessibility-tree automation compares to Sider. No credit card required.