Gemini is not most developers’ default coding assistant, and Anthropic’s Claude Opus 4.7 still leads the headline coding benchmarks. But Gemini 3.1 Pro has four genuine wins worth knowing, and one looming change every Gemini-using developer needs on their calendar: the gemini CLI and the Gemini Code Assist IDE extensions stop serving free, AI Pro, and AI Ultra users on June 18, 2026, with Google steering everyone to its new Antigravity platform. This guide tells you where Gemini earns the tab and where to switch.
TL;DR
- Gemini 3.1 Pro scores 80.6% on SWE-bench Verified (as of June 2026) versus Claude Opus 4.7 at 87.6%. Strong, not the top of the table.
- Its real edges: a 1M-token input context (whole mid-size repo at once), top frontend/UI generation (#1 on WebDev Arena), tight Google-ecosystem context (Firebase, Apps Script, Android), and a generous free Code Assist tier (~6,000 code requests/day).
- Migrate before June 18, 2026: the consumer
geminiCLI and Code Assist IDE extensions are being retired in favor of Antigravity CLI / Antigravity 2.0. Enterprise/Standard Code Assist licenses are not affected. - Switch to Claude Code for long multi-file refactors and reasoning-heavy logic; switch to ChatGPT when you want GPT-5.5’s agentic terminal work.
Who this is for
Developers at Workspace shops where Gemini is provisioned by default, anyone already paying $19.99/mo for Google AI Pro (formerly “Gemini Advanced”), and developers evaluating Gemini as a free or secondary coding helper alongside Claude or ChatGPT.
The June 18, 2026 migration you can’t ignore
At Google I/O on May 19, 2026, Google announced that the standalone gemini CLI and the Gemini Code Assist IDE extensions will stop serving requests for the free “Code Assist for individuals” tier, Google AI Pro, and Google AI Ultra on June 18, 2026. The replacement is Antigravity — an agent-first dev platform with a VS Code-based IDE, a standalone desktop “Agent Manager,” and Antigravity CLI (a Go-based terminal successor to Gemini CLI that keeps Skills, Hooks, Subagents, and Extensions as plugins).
What this means in practice:
| If you are… | What happens June 18, 2026 | What to do |
|---|---|---|
| Free Code Assist individual user | gemini CLI + IDE extension stop serving | Install Antigravity CLI / IDE (free tier with ~5-hour rate-limit refresh) |
| Google AI Pro ($19.99) / AI Ultra ($99.99) | Same retirement | Move to Antigravity; your subscription carries over |
| Code Assist Standard / Enterprise | No change | Keep existing tooling |
| Code Assist for GitHub via Google Cloud | No change | Keep existing setup |
If you script anything against the consumer gemini CLI today, port it to Antigravity CLI inside the ~30-day window. The Antigravity free tier includes Gemini 3.1 Pro plus Claude and open-weight models behind a shared agent harness.
Where Gemini genuinely wins
1. Whole-repo context. Gemini 3.1 Pro accepts a 1,048,576-token input window (output capped at 65,536 tokens). You can paste a mid-size codebase and ask cross-file questions — “trace this data-transformation bug through the three service layers” — without chunking. In Google’s own bug-isolation tests, 3.1 Pro fixed 14 of 18 cross-file bugs on the first try at Medium thinking. Claude Opus 4.7 and Sonnet 4.6 also offer 1M-token context, so this is parity at the top, not a Gemini monopoly — but it’s a real advantage over a stock ChatGPT Plus session (~320 pages in-app; the full 1M is only on the $200 Pro plan).
2. Frontend and UI generation. Gemini 3.1 Pro sits at the top of WebDev Arena (≈1,487 Elo as of June 2026) and can emit working, animated SVGs and React/Vue components from a prompt. For “build me a landing page section” or “convert this Figma description to a component,” it’s one of the strongest options available.
3. Google-ecosystem code. This is where Gemini’s native context still beats a general assistant: Firebase setup and Cloud Functions, Apps Script for Sheets/Docs/Gmail automation, Android (Kotlin + Jetpack Compose) via Android Studio integration, and Sheets formulas generated in-cell. If your stack lives in Google Cloud, Gemini usually has fresher, more idiomatic answers. (For deep Android work, see our Gemini for Android guide.)
4. A genuinely generous free tier. Free Code Assist for individuals includes roughly 6,000 code-related requests and 240 chat requests per day — far more headroom than free ChatGPT or Claude give for coding. Google also offers copyright indemnification on generated code, including on the free tier.
Where to switch instead
| Task | Reach for | Why |
|---|---|---|
| Long multi-file refactor across a real repo | Claude Code (Opus 4.7) | 87.6% SWE-bench Verified; built for agentic file edits |
| Reasoning-heavy logic / algorithm design | Claude Opus 4.7 or ChatGPT GPT-5.5 “Thinking” | Higher SWE-bench Pro (Opus 64.3%, GPT-5.5 58.6%, Gemini 54.2%) |
| Agentic terminal / command-line tasks | GPT-5.5 | Leads Terminal-Bench 2.0 (82.7% vs Gemini ~68%) |
| Rust / Haskell / less-common languages | Claude | Gemini has historically been weaker here |
The honest summary: Gemini 3.1 Pro is a strong second pick that becomes a first pick inside Google’s ecosystem. For a fuller head-to-head, see ChatGPT vs Claude vs Gemini.
A practical workflow
- Pick the right surface. In-app Gemini (gemini.google.com) for quick lookups and Sheets/Docs-embedded code; Antigravity IDE/CLI for repo-scale agentic work after June 18.
- Always tag language + framework version. Gemini is sensitive to version-specific syntax — write
Kotlin 2.2 / Jetpack Compose 1.9, not just “Kotlin.” - For repo bugs, paste, don’t upload. Gemini’s code-file upload handling is less reliable than pasting code directly into the prompt; paste the failing function plus the full error string.
- Ask for options before code. “List 2 approaches with tradeoffs, wait for me to pick” catches design mistakes before you get 200 lines of the wrong thing.
- A/B against your usual assistant on anything non-Google: same prompt to Gemini and Claude/ChatGPT, ship whichever output you can actually use.
- Run everything locally before trusting it. No 2026 model — Gemini, Claude, or GPT — is reliable enough to merge untested. Treat output as a first draft.
Worked example: a Firebase Cloud Function bug
Paste the failing function plus the exact error (for example FirebaseError: Function failed on loading user code) into Gemini and ask: “Why is this failing, and what is the minimal fix?” Gemini’s Firebase context usually surfaces the cause — a missing await, a cold-start timeout, a wrong runtime version. Verify the suggested fix against the official Firebase Functions docs before deploying, then redeploy with firebase deploy --only functions.
Common mistakes
- Reaching for Gemini on its weak languages (Rust, Haskell, advanced C++) when Claude is one tab away.
- Trusting Sheets formulas without testing edge rows — empty cells, mixed types, and trailing blanks break more AI-written formulas than any other input.
- Asking for a one-shot refactor of a large file. You usually get a plausible-looking but subtly broken version. Refactor in small, testable steps instead.
- Letting Apps Script hit external APIs with no rate-limit or retry handling — Apps Script quotas are strict and silent failures are common.
- Building automation against the consumer
geminiCLI after May 2026 without an Antigravity migration plan.
Copy-ready prompt
Language: [language] [version]
Framework: [framework] [version]
Goal: [one sentence]
Constraints: [perf / style / deps]
Existing code:
[paste your code here]
First, list 2 approaches with tradeoffs.
Wait for me to pick before writing any code.FAQ
Is Gemini 3.1 Pro good enough to replace Claude or ChatGPT for coding? For Google-ecosystem work, frontend generation, and whole-repo context: yes, it’s competitive. For top-tier multi-file refactors (Claude Opus 4.7, 87.6% SWE-bench Verified) and agentic terminal tasks (GPT-5.5, 82.7% Terminal-Bench 2.0), it’s still the second pick as of June 2026.
Do I need to do anything before June 18, 2026?
If you use the consumer gemini CLI or the Gemini Code Assist IDE extension on the free, AI Pro, or AI Ultra tier, yes — install Antigravity CLI / Antigravity 2.0 before that date, or your tooling stops serving requests. Standard and Enterprise Code Assist licenses are unaffected.
Is Gemini coding free? Largely, yes. Free Code Assist for individuals gives ~6,000 code requests/day, and the Antigravity free tier includes Gemini 3.1 Pro with rate limits. Google AI Pro at $19.99/mo (formerly “Gemini Advanced”) raises the limits and adds 1M-token context in the app.
What context window does Gemini 3.1 Pro support? 1,048,576 input tokens with up to 65,536 output tokens (as of June 2026) — enough to load a mid-size repository and reason across files.
What about Code Assist or “Duet”? Those are the IDE-integrated variants of the same underlying Gemini models. For individuals they’re being folded into Antigravity; for Standard/Enterprise seats they continue as-is.
Related
- ChatGPT for Coding
- ChatGPT Coding Workflow
- ChatGPT vs Claude vs Gemini
- Gemini for Sheets — Formulas + Insights
- Gemini for Android
Tags: #Gemini #Tutorial #AI coding #Workflow