Grok
Free tier available
- Free$0
- X Premium$8/mo
- X Premium+$40/mo

Grok
Our pickPerplexity Comet
Tier-list head-to-head. Perplexity Comet takes the A-tier slot — here's the breakdown.
Spec sheet
| Tier | B-tier | A-tierwin |
| Overall score | 7.5 / 10 | 8.4 / 10win |
| Free tier | Yes | Yes |
| Starting price | $0 | $0 |
| Best for | People who live on X/Twitter and want an AI that can tap into that data in real-time. | Users who already use Perplexity for search and want an agent browser that can complete multi-step tasks (b… |
| Last reviewed | 2026-05-21 | 2026-04-17 |
Head-to-head
Rated 1-10 on the same rubric across all 130 tools we cover.
What you'll pay
Look past the headline number -- entry-tier limits drive most cost surprises.
Free tier available
Free tier available
Grok 4.20 benchmarks — Perplexity Comet has no published benchmarks
| Benchmark | Description | Score |
|---|---|---|
| MMLU | Knowledge across 57 subjects | 88.5% |
| GPQA Diamond | Graduate-level science questions | 85% |
| HumanEval | Python code generation | 90% |
| Humanity's Last Exam | Frontier difficulty questions | 50.7% |
The decision
Use-case anchors and category strengths, side by side.
People who live on X/Twitter and want an AI that can tap into that data in real-time. Also good for users who find mainstream chatbots too sanitized and want something with more personality.
Visit GrokUsers who already use Perplexity for search and want an agent browser that can complete multi-step tasks (booking, research, shopping, document summarization) across tabs. Also a strong introduction to the AI-browser category for anyone curious but unwilling to pay $200/mo for a preview -- the 2026-03-18 free rollout makes evaluation risk-free.
Visit Perplexity CometBottom line
Perplexity Comet edges out Grok by 0.9 points (8.4 vs 7.5) -- a A-tier vs B-tier split that's narrow but real. Not a blowout; both belong on a shortlist. The score gap shows up most clearly in the categories that matter for Perplexity Comet's strengths, so if those categories are your priority, the lead translates.
Pricing-wise, both tools have a free tier (Grok starts $0, Perplexity Comet starts $0), so you can test either without committing. Compare what each free tier actually unlocks -- usage caps, model access, and feature gates differ a lot more than the headline price suggests, especially as both vendors have tightened limits in 2026.
By use case: pick Grok when people who live on x/twitter and want an ai that can tap into that data in real-time. Pick Perplexity Comet when users who already use perplexity for search and want an agent browser that can complete multi-step tasks (booking, research, shopping, document summarization) across tabs. The two tools aren't fighting for the same person -- they're aiming at adjacent jobs that occasionally overlap. If you're squarely in Perplexity Comet's lane, the tier-list ranking and the use-case fit point the same direction; if you're in Grok's lane, the score gap matters less than the fit.
Bottom line: Perplexity Comet is the safer default for most readers, but Grok is competitive enough that the tie-breaker is your specific workload, not the spec sheet.
Keep digging
Full Grok review
Tier B · 7.5/10
Full Perplexity Comet review
Tier A · 8.4/10
Grok alternatives
Other tools in this lane
Perplexity Comet alternatives
Other tools in this lane
Built from our daily AI-tool sweep, last touched May 21, 2026. Honest tier-list reviews — no affiliate-link pieces disguised as advice. See the rubric or how we review.