# HighlightGPT vs Sider

HighlightGPT records 0 monthly visits with — month-over-month growth and Paid pricing. Sider records 2,644,740 monthly visits with -10.6% growth and Freemium pricing.

| Metric | [HighlightGPT](https://openaitools.app/tool/highlightgpt) | [Sider](https://openaitools.app/tool/sider) |
| :--- | :--- | :--- |
| Website URL | https://chromewebstore.google.com/detail/highlightgpt/eehibkoimhbmcaaifkmhghofocfbeooo | https://sider.ai |
| Categories | AI Answer, Large Language Models (LLMs), AI API, AI Assistant | AI Assistant, AI Chatbot, AI Writing Assistants, AI Reader |
| Pricing Model | Paid | Freemium |
| Monthly Visits | 0 | 2,644,740 |
| MoM Growth Rate | — | -10.6% |
| Primary Market | Global | United States |
| Direct Visits | 0 | 1,699,535 |
| Review Score | 4.1 | 4.5 |
| Saved Count | 0 | 31 |
| Supported Platforms | Browser Extension | Website |

## HighlightGPT

HighlightGPT exists for the moment when a sentence on a webpage does not quite make sense and you do not want to break your reading flow to open a separate chat tab. You highlight the difficult passage and the extension sends it, together with a configurable amount of surrounding page text, to an OpenAI model that returns a plain-language explanation. Because the surrounding paragraph, heading and nearby argument are included, the answer tends to reflect what that sentence means in this specific article rather than a generic dictionary definition.

The extension exposes three levels of context so you can trade accuracy against cost: higher values pull in more of the page and give richer answers, lower values keep requests small and cheap. If a selection is too large for the model's request limit, HighlightGPT automatically reduces how much page content it ingests so the request still goes through. Double-click highlights are deliberately ignored, which prevents accidental triggers while you are simply selecting text to copy.

Setup is minimal but does require an OpenAI API key, and every explanation you generate is billed against that key. The project is a small, single-developer tool published under the name Sacrosaunt, and it upgraded its underlying model to GPT-4o in version 1.1.3. It is best understood as a focused reading aid rather than a full AI assistant suite.

**Pricing & Plans:** The extension itself is free to install, but it is not usable without your own OpenAI API key. You pay OpenAI directly for the tokens each explanation consumes, and larger context settings increase that cost. There is no separate subscription sold inside the extension.

- **In-place explanations:** Highlight a confusing sentence and receive a short explanation without leaving the page or opening another tab.
- **Three context levels:** Choose how much surrounding page text is sent along with your selection to balance answer quality against API cost.
- **Automatic request trimming:** When a selection plus page context exceeds the request size limit, the extension automatically lowers how much page content it ingests.
- **Double-click protection:** Accidental highlights created by double-clicking are ignored, so the tool only fires when you deliberately select text.
- **Bring-your-own-key design:** Runs against your personal OpenAI API key, keeping you in control of model choice, quota and spend.

**Strengths:** Explanations use surrounding page text, so answers match the article rather than a generic definition; No context switching — you stay on the page you are reading; Adjustable context depth lets you control how much you spend per explanation; Simple, single-purpose design with automatic handling of oversized requests

**Limitations:** Requires your own OpenAI API key, which adds setup friction for non-technical users; High context settings can consume your OpenAI quota quickly; Small user base and a narrow feature set — it explains text and little else

[Profile (Markdown)](https://openaitools.app/tool/highlightgpt.md)

## Sider

Sider's premise is that you should not have to leave the page you are reading to use an AI assistant. Its sidebar overlays the browser, detects the content in view, and responds with chat, summaries, translations or explanations using frontier models from multiple providers. The result is a lightweight research and reading workflow: highlight a paragraph, ask for a simpler explanation, translate a PDF and keep the original in sight.

Recent versions push Sider beyond chat. Sider Hand is a browser agent that works across real websites and uses your logged-in sessions to carry out multi-step jobs such as comparing prices while shopping, filling forms, doing cross-site research or triaging a Gmail inbox. Sider Code goes the other way, letting you instruct changes to a website's appearance or behaviour in plain language and preserving the customisation for next time. A Create module generates images, videos, slides and documents from the same panel.

Pricing moves from a limited free tier to credit-based paid plans aimed at heavier users. Lower plans suit occasional chat, summarisation and translation, while higher tiers add a dedicated cloud computer that keeps the browser agent running around the clock and a larger monthly credit allowance. Sider ships as browser extensions for Chrome and Edge plus desktop and mobile apps for macOS, Windows, iOS and Android, and is used by a very large installed base.

**Pricing & Plans:** Freemium. Free tier available with limited credits; paid plans advertised at roughly US$10/month for occasional use up to around US$100/month at the top tier, with higher credit allowances and a dedicated cloud computer on the upper plans.

- **AI sidebar on any page:** A persistent panel that reads the page you are on and answers follow-ups with GPT, Claude or Gemini without copying content into another tab.
- **Summarise and chat with documents:** Summarise long articles, PDFs and YouTube videos, extract key points, and ask detailed questions about the source material.
- **Translation and read-aloud:** Translate webpages, PDFs and images, compare bilingual output side by side, and have content read aloud for review on the move.
- **Sider Hand browser agent:** Delegate multi-step tasks across real websites — price comparison, form filling, research and inbox triage — using your existing logged-in sessions.
- **Sider Code page customisation:** Describe a change in plain words and have Sider restyle or simplify any website, remembering the modification for future visits.

**Strengths:** Works inside the browser you already use, with no context switching; Access to multiple frontier models from one subscription; Strong reading toolkit: PDF chat, YouTube summaries, translation and read-aloud; Increasingly capable agent features for multi-step browser tasks

**Limitations:** Useful credits run out quickly on the free and lower tiers; Model availability and quota rules change over time, so expectations must be checked per plan; Some agent and code features depend on a cloud machine and heavier plans

[Profile (Markdown)](https://openaitools.app/tool/sider.md)

## Frequently Asked Questions

### How do HighlightGPT and Sider compare in monthly traffic?

HighlightGPT has 0 monthly visits, while Sider has 2,644,740. Traffic estimates describe audience size, not product quality.

### How do their growth rates compare?

HighlightGPT has a month-over-month growth rate of —; Sider has -10.6%.

### How does pricing compare?

HighlightGPT: Paid. The extension itself is free to install, but it is not usable without your own OpenAI API key. You pay OpenAI directly for the tokens each explanation consumes, and larger context settings increase that cost. There is no separate subscription sold inside the extension. Sider: Freemium. Freemium. Free tier available with limited credits; paid plans advertised at roughly US$10/month for occasional use up to around US$100/month at the top tier, with higher credit allowances and a dedicated cloud computer on the upper plans.

## Alternatives

| # | Tool Name | Monthly Visits | MoM Growth Rate | Pricing Model | Summary | Profile (Markdown) |
| :--- | :--- | :--- | :--- | :--- | :--- | :--- |
| 1 | [ChatGPT](https://openaitools.app/tool/chatgpt-4) | 6,048,022,723 | +2.2% | Freemium | OpenAI's flagship multimodal assistant powered by GPT-6 and GPT-5.6 for reasoning, coding, and deep research. | [.md](https://openaitools.app/tool/chatgpt-4.md) |
| 2 | [Claude](https://openaitools.app/tool/claude-2) | 1,253,439,413 | +23.8% | Freemium | Anthropic's frontier AI workspace powered by Claude 5.5 for agentic coding, analysis, and nuanced writing. | [.md](https://openaitools.app/tool/claude-2.md) |
| 3 | [Monica](https://openaitools.app/tool/monica-ai) | 4,512,775 | -11.3% | Freemium | Offers a very similar browser sidebar experience with multiple AI models, but features slightly different pricing and workspace tools. | [.md](https://openaitools.app/tool/monica-ai.md) |
| 4 | [Merlin AI](https://openaitools.app/tool/merlin-ai) | 1,382,634 | +13.1% | Freemium | Provides robust browser-based summarization and prompt assistance, but lacks some of Sider's deeply integrated multi-model chat UI features. | [.md](https://openaitools.app/tool/merlin-ai.md) |
| 5 | [HARPA AI](https://openaitools.app/tool/harpa-ai) | 537,461 | +99.3% | Freemium | Excels at advanced web automation and data extraction alongside chat, but has a steeper learning curve than Sider. | [.md](https://openaitools.app/tool/harpa-ai.md) |
| 6 | [HyperWrite](https://openaitools.app/tool/hyperwrite-ai) | 255,429 | +34.4% | Freemium | AI writing assistant with autocomplete, research, and a Chrome extension | [.md](https://openaitools.app/tool/hyperwrite-ai.md) |
| 7 | [Glarity](https://openaitools.app/tool/glarity-summarize-google-and-youtube) | 188,823 | -49.6% | Freemium | Summarize YouTube, Google, and any page with AI — free in your browser | [.md](https://openaitools.app/tool/glarity-summarize-google-and-youtube.md) |
| 8 | [Kome AI](https://openaitools.app/tool/kome-ai) | 174,910 | -6.5% | Freemium | Integrates bookmark management and content composition into a clean sidebar, but has a more limited feature set than Sider. | [.md](https://openaitools.app/tool/kome-ai.md) |
| 9 | [Voilà — AI Assistant, Chat and Writer](https://openaitools.app/tool/voil-chatgpt-browser-assistant) | 152,170 | -4.8% | Freemium | Delivers streamlined inline writing and webpage summarization via a browser extension, but with fewer custom sidebar tools. | [.md](https://openaitools.app/tool/voil-chatgpt-browser-assistant.md) |
| 10 | [AnswersAi](https://openaitools.app/tool/answersai) | 61,703 | +22.6% | Paid | Snap a question, get the answer instantly | [.md](https://openaitools.app/tool/answersai.md) |

---
Source: https://openaitools.app/compare/highlightgpt-vs-sider

More Markdown: [Categories](https://openaitools.app/categories.md) · [Traffic rankings](https://openaitools.app/rankings.md) · [llms.txt](https://openaitools.app/llms.txt)