TL;DR — For Malaysian real estate agents in 2026, Gemini is the best daily driver (free, Google ecosystem, solid writing), ChatGPT is the best for complex reasoning and long documents, and Codex is the best for multi-step tasks that span multiple tools (browser, email, calendar, files). You don’t need to pick one — most top agents use 2.
- The 3 tools are converging: all three now do writing, research, image generation, and tool use — but each has a clear strength
- For Malaysian real estate specifically: Gemini wins for WhatsApp replies and property descriptions, ChatGPT wins for CMAs and strategy, Codex wins for end-to-end workflows (find listings, draft outreach, send emails)
- All three have free tiers that are enough for 1-3 active agents. The 2026 winners in Malaysian real estate will use all three, not just one
Key takeaways
- Codex is the new entrant that grew 5x in H1 2026 — it’s the only one that can autonomously use your browser, email, calendar, and files without you copying and pasting
- For Malaysian context: Gemini knows the local property market better out-of-the-box; ChatGPT needs more prompting for Malaysian specifics; Codex is the most “agentic” but less polished for pure writing
- The 80/20 answer: start with Gemini (best free tier + best writing + Google Workspace integration), add ChatGPT for complex work, try Codex when you have a real multi-step task to automate
This article is for: Malaysian real estate agents (REN/REA), agency principals, and property marketing teams evaluating which AI tool to use (or add) in 2026. Assumes you have basic familiarity with ChatGPT or Gemini. No coding required. Free tiers are enough to test all three.
Why this comparison matters now
Three AI tools dominate agent conversations in 2026: OpenAI’s Codex, OpenAI’s ChatGPT, and Google’s Gemini. All three can write property descriptions, summarise market reports, and answer questions. But they are not the same tool, and the differences matter for real estate work.
The shift that’s driving this comparison: in H1 2026, agentic AI usage grew 5x (per OpenAI’s own research). Codex accounts for 99% of AI output tokens at OpenAI internally, 63% at external organisations, and 17% at individual users — and growing. Meanwhile, 93% of Malaysian employees already use generative AI per EY’s 2025 Work Reimagined Survey, and 86% of Malaysian leaders plan to use AI agents as digital team members in the next 12-18 months per Microsoft.
For Malaysian real estate specifically, the question isn’t “which AI should I use” — it’s “which AI for which task, and can I use the free tier.” This article answers both.
Quick primer: What is each tool?
Codex
OpenAI’s agentic AI. Launched in 2025, hit mainstream in 2026. The key difference from ChatGPT: Codex can use your actual tools — browser, email, calendar, file system, terminal — to complete multi-step tasks on its own. You give it a goal, it figures out the steps.
What it does for agents: “Find 5 new Mont Kiara condo listings from last week, draft a WhatsApp message to each listing agent, and save the draft to my Drive.” Codex opens the browser, scrapes PropertyGuru, drafts 5 messages, saves them. You review, then send.
ChatGPT
OpenAI’s chat-based AI. The tool most people think of when they hear “AI.” Best-in-class for writing, reasoning, and long documents. Has the largest plugin ecosystem.
What it does for agents: Long-form content, complex analysis, custom GPTs (mini-apps for specific tasks), image generation, and now some tool use. Strong at “think through this problem with me.”
Gemini
Google’s AI. Free with any Google account. The most natural fit for the 2 billion Gmail + Workspace users. Tight integration with Gmail, Drive, Docs, Sheets, Calendar.
What it does for agents: Daily writing, research with live web access, image generation, and the best free-tier value for Malaysian agents already in the Google ecosystem. Gemini Gems (custom assistants) let you build a property-description bot trained on your agency’s voice.
Head-to-head comparison
| Dimension | Codex | ChatGPT | Gemini |
|---|---|---|---|
| Best for | Multi-step autonomous tasks | Long-form writing, reasoning | Daily writing, Google integration |
| Free tier | Limited (agentic tasks use credits) | Generous (GPT-4o mini, slower) | Generous (10-15 long chats/day) |
| Writing quality | Good, sometimes over-formal | Best (especially long docs) | Very good (especially short) |
| Research with citations | Limited | Limited (no live web in free) | Best (Google Search integration) |
| Tool use (browser, email, files) | Best (native, autonomous) | Some (via plugins, manual) | Some (Workspace integration) |
| Malaysian context awareness | Good (with prompting) | Good (with prompting) | Best (trained on more recent MY data) |
| Image generation | Yes (in free tier) | Yes (limited) | Yes (best free quality) |
| Mobile app | Yes (newer, less polished) | Yes (mature) | Yes (mature) |
| Speed | Slower (agentic tasks) | Fast | Fast |
| Data privacy (free tier) | Standard | Standard | Standard (Google policy) |
| Best ecosystem fit | Tech / engineering | Mixed | Google Workspace |
5 real Malaysian real estate workflows, tested
To pick a winner, I ran the same 5 tasks through all three tools using the Malaysian real estate context. Here’s what came out.
Workflow 1: Write a PropertyGuru description for a Mont Kiara condo
Same prompt: “Write a 150-word PropertyGuru description for a 1,250 sqft, 3-bedroom corner unit condo at Mont Kiara, 18th floor, freehold, 5 min walk to MRT Semantan, fully furnished, RM 1.1M.”
Result:
- Codex: Solid, included all keywords. Tone slightly formal. Mentioned MRT and freehold correctly.
- ChatGPT: Best writing. Most natural flow. Included all keywords. Felt like a real agent wrote it.
- Gemini: Very good. Slightly more concise. Included all keywords. Slightly more “marketing copy” tone.
Winner: ChatGPT (for pure writing quality), Gemini (for keyword density and concise format).
Workflow 2: Summarise a JPPH quarterly report
Same task: “Summarise this 80-page JPPH Q1 2026 property market report into 5 bullet points for a client email.”
Result:
- Codex: Best for this. It actually read the PDF, extracted data, and produced well-cited bullets. Saved 45 minutes.
- ChatGPT: Required uploading the PDF in chat. Good summary, no live web. 30 minutes saved.
- Gemini: Required uploading the PDF. Solid summary with Google Search cross-references. 35 minutes saved.
Winner: Codex (for autonomous PDF reading) — but all three can do this if you upload the file.
Workflow 3: Draft a WhatsApp follow-up for a lead
Same task: “Draft a WhatsApp message for a buyer who viewed a Mont Kiara unit 3 days ago, didn’t make an offer, but I have a new similar unit coming on the market next week.”
Result:
- Codex: Good. Slightly formal, needed editing. Took 2 minutes to generate.
- ChatGPT: Very good. Natural tone. Included timing and next-step. Slightly long.
- Gemini: Best. Short, warm, on-brand. Included the “new similar unit” hook naturally.
Winner: Gemini (most natural for WhatsApp), ChatGPT (close second).
Workflow 4: Create a CMA outline for a client meeting
Same task: “Outline a comparative market analysis for a 3-bedroom Mont Kiara unit, RM 1.1M asking price. Include comparable sales, market trend, valuation, and recommendation sections.”
Result:
- Codex: Solid outline. Logical structure. Listed comps from memory (some hallucinated).
- ChatGPT: Best. Detailed outline with section-by-section guidance. Referenced the right categories.
- Gemini: Good. Concise. Slightly less structured.
Winner: ChatGPT (best structured thinking for complex docs).
Workflow 5: End-to-end — “Find new listings and draft outreach”
This is the Codex-only test. Task: “Find 5 new Mont Kiara condo listings from this week on PropertyGuru, draft a WhatsApp message to each listing agent offering to bring buyers, save the drafts to my Google Drive.”
Result:
- Codex: Did it autonomously. 12 minutes. Found 4 listings (1 was already in DB), drafted 4 messages, saved to Drive. Required minor edits.
- ChatGPT: Can’t do this end-to-end. Could only help with the message-drafting step.
- Gemini: Same as ChatGPT. Could help with the message step.
Winner: Codex (only one that can do end-to-end).
Tally
| Task | Winner |
|---|---|
| Property description | ChatGPT, Gemini |
| PDF report summary | Codex (then ChatGPT/Gemini if you upload) |
| WhatsApp follow-up | Gemini (then ChatGPT) |
| CMA outline | ChatGPT |
| End-to-end workflow | Codex (only option) |
The pattern: Codex wins for autonomous multi-step tasks. ChatGPT wins for thinking and writing. Gemini wins for daily quick work in the Google ecosystem.
The 80/20 recommendation for Malaysian real estate agents
If you’re just starting with AI and can only pick one tool, pick Gemini. Here’s why:
- Best free tier. 10-15 long conversations per day, free forever, with a Google account you already have.
- Best Malaysian context. Trained on more recent and broader data; understands Malaysian property market terms better out of the box.
- Google Workspace integration. If you use Gmail, Drive, Docs, Sheets, Calendar, Gemini fits in without learning a new system.
- Gemini Gems. Custom assistants you can train on your agency’s voice. Build a “property description bot” or “WhatsApp reply bot” in 5 minutes.
If you already use ChatGPT and like it, don’t switch. ChatGPT is the best for long writing, complex reasoning, and has the biggest plugin ecosystem. The free tier (GPT-4o mini) is slower but capable.
If you have a real estate business and want to automate multi-step workflows (lead scraping, follow-up sequences, market monitoring), add Codex. It’s the only one of the three that can autonomously use your browser, email, and files. Best for 5+ agent teams or solo agents with repeatable workflows.
When to add each tool
- Day 1: Start with Gemini (or ChatGPT if you already use it). Use for property descriptions and WhatsApp replies.
- Week 2: Once comfortable, try the same tasks in ChatGPT (if you started with Gemini) or vice versa. See which you prefer.
- Month 1: If you find yourself doing the same multi-step task repeatedly (e.g., “check new listings, draft outreach, save to Drive”), try Codex. That’s the task Codex was built for.
- Month 3: Build Gemini Gems or custom GPTs for your most common tasks. This is where the 5-10 hour per week time saving kicks in.
FAQ
Is Codex replacing ChatGPT at OpenAI?
Yes, internally. Per OpenAI’s H1 2026 report, Codex accounts for 99% of AI output tokens at OpenAI. Among external organisations, it’s 63%. For individuals, it’s 17% and growing. The shift is real but not complete — ChatGPT remains the entry point for most new users.
Do I need to pay for any of these?
No. All three have free tiers. For Gemini and ChatGPT free, the limits are enough for solo agents. For Codex, the free tier covers more limited agentic tasks — heavy users will need a paid plan.
Can I use Codex for non-coding tasks?
Yes. The original Codex was code-focused, but the 2026 Codex is a general-purpose agentic AI. Real estate, marketing, research, admin — all work. The same plugins (browser, email, calendar, files) apply to any task.
Is Malaysian English handled well by all three?
Yes, with caveats. All three understand Malaysian English (lift not elevator, freehold, MRT station names, etc.). Gemini tends to do best on first try, ChatGPT needs occasional prompts to use local terminology, and Codex is similar to ChatGPT. The prompt template approach (specifying “use Malaysian English”) works for all three.
What about data privacy for client work?
Standard data policies apply to all three free tiers. Your inputs may be reviewed for safety and to improve models. For sensitive client work (CMAs with owner financials, valuation reports, M&A), upgrade to enterprise plans that exclude your data from training.
Can I use all three at once?
Yes, and many Malaysian agents do. The pattern: Gemini for daily work (free, fast), ChatGPT for complex thinking (free or paid), Codex for autonomous multi-step tasks (free or paid). The free tiers across all three are enough for 1-3 active agents.
What’s the real difference between Codex and ChatGPT?
ChatGPT is a chat interface. You ask, it answers. Codex is an agent that can use tools. You give it a goal, it figures out the steps using your browser, email, files, and calendar. For most real estate tasks, ChatGPT is enough. For multi-step automations, Codex is the step up.
Conclusion
The 2026 answer for Malaysian real estate isn’t “which AI tool” — it’s “which AI tool for which task, and which combination.” Most successful agents in 2026 use 2 of the 3 daily and try the third when they have a specific need.
If you want a structured 5-hour walkthrough of how to combine all three (plus the other 4 free tools — NotebookLM, Canva AI, Gamma, CapCut, Perplexity) into a complete agent workflow — and earn 5 LPPEH CPD Hours — my Mastering AI workshop is HRD Corp claimable, bilingual, hands-on.
Next step: Pick the tool you haven’t tried yet. Run one task through it today. See if it changes your week.
Written by Reese Tan, HRDC-Accredited AI Trainer and full-time Digital Marketing Strategist based in Malaysia. 15+ years in SME growth, corporate marketing, and content strategy. 500+ professionals trained across SMEs, corporate teams, and real estate agencies. Last updated: August 2026.