UPDATED 11 SEPTEMBER 2026
Rewritten for GPT-6 Astra, which began rolling out to ChatGPT Plus on 3 September. Model names, API pricing and tier structure all updated. One section reversed: Grok is no longer the cheaper API.
QUICK VERDICT
● ChatGPT Plus $20 wins if: you want Astra, Codex across four surfaces, 500+ integrations, persistent memory, or the widest ecosystem
● SuperGrok $30 wins if: live X data is core to your work — social listening, trend research, market sentiment
● For most professionals: ChatGPT Plus, at $10 less, and Astra widened the gap
● For developers: the API argument reversed. GPT-5.6 Luna at $0.20/M undercuts Grok 4.6 at $2/M
● The catch nobody mentions: SuperGrok tiers share one weekly pool across Chat, Imagine, Voice and Build
What Changed Since the Original Test
The original comparison ran in June. Four things have happened since, and two of them change the answer.
● GPT-6 Astra shipped 3 September and is rolling out to Plus, Pro, Business and Enterprise. Its advanced cyber capability is gated behind a separate application programme, but the model reaches ordinary subscribers
● Grok moved to 4.6, with 4.7 indicated for September and no model ID published yet
● GPT-5.4 left Codex on 31 August for ChatGPT sign-in users, replaced by GPT-5.6 Terra and Luna. API-key sessions still have it
● The DALL-E GPT retired on 30 August. Image generation continues through ChatGPT Images
The Full Comparison
| Dimension |
SuperGrok $30/mo |
ChatGPT Plus $20/mo |
Winner |
| Price | $30 | $20 | ChatGPT |
| Flagship model | Grok 4.6 | GPT-6 Astra, rolling out | ChatGPT |
| Real-time X data | Live firehose | Web search only | Grok |
| Coding agent | No dedicated agent | Codex, four surfaces | ChatGPT |
| Usage metering | One shared weekly pool | Metered per product | ChatGPT |
| Image generation | Grok Imagine | ChatGPT Images | Tie |
| Voice naturalness | Better, 300-500ms | Good, more voices | Grok |
| Custom agents | 4 slots | Unlimited custom GPTs | ChatGPT |
| Persistent memory | Limited | Strong, cross-session | ChatGPT |
| Integrations | Limited | 500+ | ChatGPT |
| Desktop app | No | Windows and Mac | ChatGPT |
| Cheapest API option | Grok 4.6 at $2/M in | GPT-5.6 Luna at $0.20/M in | ChatGPT |
The API Argument Reversed
WE GOT THIS WRONG IN JUNE, AND THE MARKET MOVED
The original version said Grok API was dramatically cheaper — $1.25 in and $2.50 out against GPT-5.5 at $5 and $30. That was accurate at the time.
It is not accurate now. GPT-5.6 Luna runs at $0.20 in and $1.20 out, which undercuts Grok 4.6 at $2 per million on input by a factor of ten.
OpenAI split its line into three tiers, and the cheap one is genuinely cheap. For high-volume simple work — classification, extraction, routing — Luna is now the budget option and Grok is not.
One caveat that matters for budgeting: GPT-5.6 Sol currently sits at $4 and $20 promotionally, reverting to $5 and $30 around 21 November. Price any migration at the rate that will exist rather than the one that does.
The Shared Pool Nobody Mentions
Paid Grok plans run on a single weekly allowance covering Chat, Imagine, Voice and Build. Generate a run of images and you have less left for research. Spend an afternoon on voice and the same applies.
ChatGPT meters per product, so image generation does not consume your Codex budget. That difference does not appear on either pricing page and it is the thing most likely to surprise a heavy user in week two.
What 30 Days Revealed — Still True
The X advantage is real and narrower than you think
Asked what people were saying about NVDA earnings in the moment, Grok surfaced investor posts from the previous half hour. ChatGPT returned a news article from four hours earlier. For live sentiment on stocks, politics and breaking news, Grok wins and it is not close.
But that matters for a specific slice of work — journalists, social managers, political researchers, analysts tracking sentiment. Everyone else is paying $10 more for something they use twice a week.
ChatGPT wins on coding, and Astra widened it
For a developer using AI daily, ChatGPT Plus with Codex is the better $20 than SuperGrok alone at $30. Grok has no equivalent to Codex — it is a strong chat model that writes code, not an agent that runs a session.
Astra arriving on Plus makes that gap wider rather than narrower, and it costs subscribers nothing extra.
Grok voice is more natural, ChatGPT voice has more features
Grok at 300 to 500ms sounds more human, redirects cleanly when interrupted, and shifts tone appropriately. ChatGPT has more voices, desktop support and Siri handoff. For driving and casual use, Grok. For desktop workflows, ChatGPT. Both are good.
Four agent slots is still a real constraint
SuperGrok Custom Agents hold persona and workflow context better than ChatGPT custom GPTs, which drift. But four slots against unlimited is a genuine limit for anyone wanting agents across several functions. The workaround is here.
Pricing — Every Tier
| Tier | Grok / SuperGrok | ChatGPT |
|---|
| Free | ~10 messages per 2 hours | Usage-limited |
| Entry paid | SuperGrok Lite — $10 | ChatGPT Go — $8 |
| Main tier | SuperGrok — $30 | ChatGPT Plus — $20 |
| Upper tier | SuperGrok Plus — $100 | — |
| Top tier | SuperGrok Heavy — $300 | ChatGPT Pro — $200 |
| X Premium+ bundle | Discounted — check current terms | N/A |
| API, cheapest tier | Grok 4.6 — $2 in | Luna — $0.20 in / $1.20 out |
| API, flagship | Grok 4.6 — $2 in | Sol — $4/$20 promo, $5/$30 from ~21 Nov |
Who Should Pay for What
ChatGPT Plus, $20
You code, or want Codex. You need integrations. You want Astra without paying more. You want persistent memory. You want one subscription that does everything adequately. This is most people.
SuperGrok, $30
Live X data is core to your daily work. You want Grok voice for hands-free use. You want Custom Agents with strong persona persistence. If you already pay for X Premium+, check the current bundle terms — the maths changes.
Both, $50
You use AI four or more hours a day. Grok for live research and voice, ChatGPT for coding and structured work. Cheaper than the value lost forcing one tool to do both jobs badly.
Neither, if you are casual
Both free tiers are genuinely usable. Grok free caps around ten messages per two hours, which is enough to try and not enough to rely on. ChatGPT free is more generous.
FAQ
Is SuperGrok worth $30 against ChatGPT Plus at $20?
For most professionals, no — and GPT-6 Astra arriving on Plus in September widened the gap. SuperGrok gives you one thing ChatGPT cannot match: live X firehose data. If that is core to your work it is worth the premium. Otherwise Plus is better value.
Does ChatGPT Plus include GPT-6 Astra?
Yes. Astra began rolling out on 3 September to Plus, Pro, Business and Enterprise. The advanced cyber capability is gated behind a separate application programme, but the model itself reaches ordinary subscribers at no extra cost.
Which API is cheaper now?
OpenAI, which is a reversal. GPT-5.6 Luna runs at $0.20 in and $1.20 out against Grok 4.6 at $2 per million. Grok was the cheap option in June and no longer is.
What is the shared weekly pool?
Paid Grok plans meter Chat, Imagine, Voice and Build against one weekly allowance, so heavy image generation reduces what is left for research. ChatGPT meters per product. Neither pricing page states this clearly.
Is Grok 4.7 out?
Not as of 11 September. Musk indicated an early-to-mid September window, and there is still no model ID at docs.x.ai, no published price and no benchmark card.
Related: ChatGPT Plus vs Pro now Astra ships · What GPT-6 Astra actually shipped with · SuperGrok Lite vs SuperGrok · Grok Custom Agents guide · Model release tracker