AI Search Engine Comparison — Perplexity vs ChatGPT vs Gemini vs Grok

An AI answer engine reads the live web, then writes a single sourced answer instead of handing you ten blue links. This page lines up the 7 engines a Sri Lankan student, freelancer or small-business owner actually has to choose between — Perplexity, ChatGPT Search, Google Gemini (and AI Mode), Microsoft Copilot, Grok, Claude and DeepSeek — across the dimensions that decide which one you pay for.

1. The comparison table

The table is a curated, sourced dataset — not a benchmark and not an opinion score. Each row records seven facts straight from the provider's own pages: the underlying model, what the free tier gives you, the entry paid price, whether answers show citations, whether it reads the live web, file and image upload, public-API availability, supported platforms, and whether the provider trains on your conversations. The filter chips (free tier, shows citations, has API) and the sort control run entirely in your browser; nothing is sent anywhere.

2. The cost calculator

Capabilities tell you which engine; the calculator tells you the bill. It is deterministic — pick a service, a plan, a seat count and a billing period, and it applies the published price:

monthly billing → monthlyUSD = per_seat_price × seats; annualUSD = per_seat_price × 12 × seats

annual billing → annualUSD = annual_plan_price × seats; monthlyUSD = annualUSD ÷ 12

Annual-plan prices store the provider's published yearly figure, so a discounted annual plan (Perplexity Pro and Claude Pro both bill less than 12× monthly) shows up as a real saving. A second arithmetic route, annualSavingsUSD(), recomputes month-to-month-for-a-year minus the annual plan and surfaces the difference as a verifiable “save USD X/yr” note.

3. The LKR column is indicative

USD figures multiply by a fixed CBSL middle rate of Rs 300per USD to produce the rupee columns. This is a constant, not a live feed — your bank's actual rate plus FX margin and card fees will differ by a few percent. For a live USD-to-LKR rate with Wise, Payoneer and Skrill fee comparisons, use the Freelancer USD-LKR calculator in Related tools.

4. Cross-checks

The data module exports verifyWorkedExamples() (which recomputes the worked examples below, including the zero-seat and 501-seat error cases) and verifyDatasetIntegrity() (which asserts unique ids, non-negative prices, an https source on every row, and that each “best for” pick points at a real engine). Both run at typecheck time, so a typo in a price during a quarterly update fails the build instead of shipping silently.

• Perplexity — Help Center & FAQ (plans, citations, models)
• OpenAI — Introducing ChatGPT Search
• OpenAI — ChatGPT pricing (Free, Plus, Team)
• Google — AI plans (AI Pro, AI Ultra)
• Google — Gemini app & AI Mode
• Microsoft — Copilot pricing (Free, Pro)
• xAI — Grok plans (Free, SuperGrok)
• Anthropic — Claude web search
• DeepSeek — web chat with search
• Central Bank of Sri Lanka — Exchange Rates (indicative LKR column)

Plans, prices, citation behaviour and data-training policies were last cross-checked against the official sources on 2026-06-30. LKR figures are indicative, using a fixed CBSL middle rate of Rs 300 per USD. The dataset is reviewed quarterly and whenever a provider changes a plan.