Sider alternative: Copilotly compared

As of November 2026, Sider's official Chrome Web Store listing describes a larger tool set than Copilotly has. Sider's own website returned an HTTP 403 to our fetcher, so everything below is what that listing says, not what we measured in the product.

Features Sider lists that Copilotly does not

• Group chat that compares answers from several models side by side.
• Image tools beyond generation: the listing names background removal, inpainting and upscaling as well as text-to-image. Copilotly has image generation but not those editing tools.
• Audio files and images as chat input, and PDF and image translation. Copilotly chats with PDF, Word, Excel and CSV files and does not list audio.
• Text-to-speech, an essay writer, an outline tool and a prompt library.
• Search-engine answers shown on results pages, and Gmail writing help.

Scale and track record

The listing shows "5,000,000 users" and a 4.9 rating from 114.7K ratings, and its description says it is trusted by over 6 million weekly active users across Chrome and Edge. Those are Sider's own figures as shown on its listing. A product that large has had its rough edges found and fixed, and that is a fair reason to stay with it. The listing also showed version 5.35.7 updated November 6, 2026, so it is actively maintained.

If you rely on group chat, the editing tools or audio input, Sider is the better fit today and switching would cost you a feature.

Copilotly overlaps with Sider on the main jobs: a sidebar with several models, web search with sources, page and YouTube summaries, file chat and translation. The differences are in how some of those jobs work.

Rewrite anywhere, with a diff

Select text on any page and a toolbar appears with direct actions and a Ctrl/Cmd+K command menu. Rewrite anywhere has tone and length pickers, a word-level diff against your original, versions and undo, and replaces the selection in place or inserts into the field.

Bilingual page translation

Page translation shows the original and the translation together, with a progress bar and view modes. Sider's listing also lists full-page translation, so this is a match on capability, not a lead.

Chat, search and research

Chat reads the current page and YouTube videos, runs web search with cited sources, and has a deep research mode with a live plan. Chat with PDF, Word, Excel and CSV is built in.

Your own key, never metered

Requests on your own API key are never metered by Copilotly. Sider's listing also names a "BYO API Key" option, so this is another match; the difference is only the Copilotly side of the arrangement.

The model picker spans OpenAI, Anthropic, Google, xAI, DeepSeek, Mistral and more. See ChatGPT and Claude for how each is used.

Sider's column is limited to what its Chrome listing says. A blank-looking answer means the listing does not say, not that the feature is missing.

	Sider (Chrome listing)	Copilotly
Models named	ChatGPT, Claude, DeepSeek, Gemini, Grok, Llama	GPT, Claude, Gemini, Grok, DeepSeek, Mistral, Qwen, Kimi
Group chat across models	Yes	Not offered
Chat with files	Images, PDFs, web pages, audio	PDF, Word, Excel, CSV, web pages, YouTube
Image tools	Text-to-image, background removal, inpainting, upscaling	Text-to-image
Rewrite in place with diff and undo	Contextual help in input boxes, rewording, tone	Yes, with word-level diff and versions
Page translation	Full-page and video translation	Bilingual page translation
Bring your own API key	Yes	Yes, never metered
Browsers	Chrome and Edge named	Chrome, Edge, Firefox, Brave, Opera
Price	Not stated on the listing	Free; Pro $6.99/week, $19.99/month or $149.99/year

For Sider's current plans and limits, read sider.ai directly. We cannot quote them.

Copilotly Free gives you fast models within a token allowance, plus per day: 10 premium-model messages, 5 web searches, 3 images, 1 deep research run, 3 full-page translations and 5 voice drafts.

Copilotly Pro is $6.99/week, $19.99/month or $149.99/year, with a 7-day free trial for first-time subscribers. The full breakdown is on the pricing page and the free plan page explains each daily limit.

We could not retrieve Sider's pricing, so we do not compare prices. What we can say is how to compare them fairly: count the premium-model messages you send in an ordinary week, check how each service treats them on its free tier, and look at how each bills (weekly, monthly, yearly) before you pay.

Stay with Sider if

you use group chat, the image editing tools or audio files, you are happy with it today, or you want the product with the larger user base. Switching only makes sense if something specific below applies to you.

Try Copilotly if

you use Firefox, Brave or Opera and want the same extension everywhere, you want in-place rewriting with a visible diff and undo, you want deep research with a live plan, or you want a free plan that includes daily premium-model messages and needs no card. For other comparisons see Monica, Merlin and MaxAI, or the roundup of best AI copilots by profession.

Nothing needs to break. Extensions install side by side, so you can move one task at a time.

1. Write down what you actually use. Open Sider and note the three features you used this week. If one of them is group chat or image editing, keep Sider for that.
2. Install Copilotly from the download page and sign in with a free account.
3. Move your own key, if you use one, into Copilotly's settings. Copilotly's bring your own key page covers the providers.
4. Re-create custom prompts. There is no import from Sider. Paste your best prompts into custom instructions, or keep them in a note and paste when needed.
5. Check shortcuts. Copilotly opens with Alt+C. If another extension already uses it, change it at chrome://extensions/shortcuts.
6. Remove Sider only after a week. In Chrome, right-click its toolbar icon and choose Remove from Chrome, or go to the three-dot menu, Extensions, Manage extensions, and click Remove.