How do their growth rates compare?

Second Opinion has a month-over-month growth rate of 0%; ZeroGPT Plus has +21%.

How does pricing compare?

Second Opinion: Freemium. The extension is free to install and use. You supply your own Grok API key, so you pay only for token usage per check. No subscription fees or hidden costs for the extension itself. ZeroGPT Plus: Freemium. Free tier: about 500 words plus 250 AI-detector words and 3 full reports, with standard detection (login required for the broader free toolset). Paid subscriptions add higher monthly word allowances (100,000, 300,000, and unlimited tiers), file uploads, the advanced/ultra AI humanizer, ad-free experience, and priority processing. Enterprise plans offer custom volumes, API access, and batch processing. Payments are handled by Paddle; word credits reset each cycle and the site states refunds are not offered.

What are alternatives to Second Opinion and ZeroGPT Plus?

Other tools in related categories include ZeroGPT, GPTZero, Undetectable AI, Sider, Originality.ai.

Second Opinion vs ZeroGPT Plus — Traffic (0 vs 134.64K), Pricing & Verdict

Open AI Tools

Second Opinion vs ZeroGPT Plus — Traffic (0 vs 134.64K), Pricing & Verdict | Open AI Tools

Side-by-Side Traffic & Specification Matrix

Dimension / Metric	Second Opinion	ZeroGPT Plus
Official Domain	secondopinion.so	zerogpt.plus
Pricing Model	Freemium	Freemium
Monthly Visits	0 (0)	134.64K (134,635)
MoM Traffic Delta	0 (0%)	+23.41K (+21%)
Primary Market & Share	🌐 Global (—)	🇺🇸 United States (27.8%)
Direct Visits / mo	0	70.61K
User Rating	3.9	3.8
Supported Platforms	Website	Website

Second Opinion

Fact-check and bias-check any text while you browse

Right-click fact-checking

Highlight any passage on a website, social platform, or news article and choose Get Second Opinion to receive an analysis without leaving the page.

Accuracy verification

The model assesses the specific claims in the highlighted text and flags statements that appear unsupported or misleading.

Bias and framing detection

Beyond true or false, it points out loaded wording, one-sided framing, and rhetorical choices that shape interpretation.

Alternative perspectives

Each check surfaces opposing viewpoints and context, so you can compare how the same facts are presented elsewhere.

Strengths & Pros

+Works inline through a right-click, so verification does not break your reading flow
+Goes beyond true or false to flag bias, framing, and missing perspectives
+Free extension with pay-only-for-usage token costs through your own API key
+Available on Brave, Edge, and other Chromium browsers as well as Chrome