Comparison

DeepSeek vs ChatGPT

DeepSeek vs ChatGPT in 2026 — how the free, open-weight Chinese model and the all-round paid assistant compare on price, benchmarks, features and privacy, and which one to choose.

Updated October 2026

Quick answer: DeepSeek and ChatGPT answer two different questions. DeepSeek is the value and openness champion: it is completely free with no paid tier, runs the open-weight DeepSeek V4 (MIT licence) with a 1M-token context, and its API is roughly 25 times cheaper on output than ChatGPT’s flagship at off-peak rates (about 13 times at peak). ChatGPT is the more capable and far more complete assistant: it runs GPT-6 Astra, OpenAI’s flagship on every paid tier since 5 September 2026, and adds image generation, Sora video, real-time voice, memory and autonomous agents that DeepSeek does not have. The caveat that decides it for many: DeepSeek’s app stores your data on servers in China and is banned or restricted by a growing list of governments, while ChatGPT keeps data in the US (and shows ads on its Free and Go tiers in a growing number of markets). Pick DeepSeek to spend nothing or to self-host an open model; pick ChatGPT for the most capable, feature-rich assistant and safer data handling.

At a glance

Open weights vs a closed flagship

This is the structural difference that drives every other one. DeepSeek is an open-weight model you can run yourself; ChatGPT is a closed, proprietary product you can only rent.

DeepSeek runs DeepSeek V4, released as a preview on 24 April 2026 and published under the permissive MIT licence. It ships in two Mixture-of-Experts sizes — V4-Pro (1.6 trillion parameters, 49 billion active) and V4-Flash (284 billion, 13 billion active) — both with a 1-million-token context window. Because the weights are open, the exact model in the app can be downloaded from Hugging Face, self-hosted, fine-tuned and used commercially. No closed product can match that.

ChatGPT runs GPT-6 Astra, OpenAI’s flagship on every paid tier since 5 September 2026. It succeeded GPT-5.6 Sol, which became generally available on 9 July 2026, replaced GPT-5.5 at the top of the line, and is still selectable. Astra is a closed, proprietary model available only through the ChatGPT app and the OpenAI API — there are no weights to download. On the paid tiers you get OpenAI’s flagship tuned to work with ChatGPT’s own tools, memory and agents; DeepSeek gives you one strong model and a reasoning toggle.

Both apps default to a lighter model for everyday speed. DeepSeek exposes DeepThink, its R-series reasoning mode with visible chain-of-thought, on the free app at no cost. ChatGPT’s Free and Go tiers have run a lighter GPT-5.6 Luna model by default since the week of 6 August 2026, with unlimited text chats and a Think button, rather than the GPT-6 Astra flagship, which is reserved for paying users. For where every model ranks, see best AI models.

Intelligence and benchmarks

ChatGPT’s flagship is the more capable model; DeepSeek V4 is the strongest you can get for free or self-host. On the independent Artificial Analysis Intelligence Index, which aggregates capability across many evaluations, ChatGPT’s flagships have led DeepSeek V4-Pro clearly. The index was re-based as v4.3 on 7 September 2026, so older scores sit on a different scale and are shown separately.

On the earlier v4.1 scale, DeepSeek V4-Pro scored 52, among the highest of any open-weight model at the time (alongside Kimi K2.6 at 54), against 55 for GPT-5.5 and 59 for GPT-5.6 Sol. On the current v4.3 scale, GPT-6 Astra scores 53, well above Sol’s 47, so ChatGPT’s flagship sits a clear step above DeepSeek on aggregate intelligence. The US government’s NIST CAISI evaluation reached the same conclusion in plainer terms: V4-Pro is the most capable Chinese model it has tested, but roughly eight months behind the leading US models.

The gap on everyday questions is much smaller than those numbers suggest. On knowledge and science, DeepSeek V4-Pro posts 90.1% on GPQA Diamond and 87.5% on MMLU-Pro (both vendor-reported), which is frontier-adjacent. For most factual and reasoning tasks the two feel close; the difference shows up on the hardest, multi-step problems, where ChatGPT’s flagship pulls ahead.

Coding

This is closer than the intelligence gap, and it depends on what you optimise for. On the standard SWE-bench Verified benchmark the two flagships are within a couple of points, but the numbers are not measured the same way.

DeepSeek V4-Pro scores 80.6% on SWE-bench Verified, but that is a DeepSeek-run figure on the older, Python-only variant and reads as a ceiling. GPT-5.5’s 82.6% on the same benchmark was independently measured by vals.ai, so the real gap is likely wider than two points. On the harder, memorisation-resistant SWE-bench Pro, both GPT-5.5 (58.6%) and GPT-5.6 Sol (64.6%) lead V4-Pro (~55%); GPT-6 Astra, ChatGPT’s flagship since September, has published no SWE-bench figure, but it scores 62 on the current Artificial Analysis Coding Agent Index, level with Claude Fable 5.1. (GPT-5.6 Sol’s 80 on that index was its July launch reading on an earlier scale and is not comparable.) Ignore any “88.7% SWE-bench Verified” figure quoted for GPT-5.5; it is not from an independent evaluator.

Where DeepSeek wins on code is cost, not quality. V4-Pro output is roughly 25 times cheaper than ChatGPT’s GPT-6 Astra flagship off-peak ($1.98 versus $50 per million tokens), and about 13 times cheaper at peak, which makes it the rational choice for high-volume coding agents and for developers who want to self-host. If you want the single strongest coding result, ChatGPT’s flagship with Codex is ahead; if you want frontier-adjacent code at a fraction of the price, DeepSeek V4 is unmatched. Full detail in best AI for coding.

Pricing and value

On price, nothing beats DeepSeek — it is free, and its API is the cheapest from any major lab. This is the whole reason to choose it.

The DeepSeek app is completely free with no paid consumer tier and no advertised message caps — you get the full DeepSeek V4 model, DeepThink reasoning and a 1M-token context at no cost. On the API, V4-Pro costs $0.66 per million input tokens and $1.98 per million output off-peak — DeepSeek moved to time-of-day billing in August 2026, with peak hours (01:00–04:00 and 06:00–10:00 UTC weekdays) at double those rates — and V4-Flash is cheaper still at $0.22 / $0.66. ChatGPT’s current flagship GPT-6 Astra costs $10 / $50 — about 25 times V4-Pro’s off-peak output price and 13 times its peak; its predecessor GPT-5.6 Sol costs $4 / $20 on a promotion running to 21 November 2026 (list $5 / $30) — about 10 times V4-Pro’s off-peak output price and 5 times its peak — with cheaper Terra ($2 / $12) and Luna ($0.20 / $1.20) tiers below it, both cut on 30 July 2026.

ChatGPT’s paid plans buy capability and breadth the free DeepSeek app cannot: the GPT-6 Astra flagship, agents, image and video generation, and higher limits. But if your budget is the deciding factor, DeepSeek’s free app and rock-bottom API pricing win outright, and its open weights let you run the model with no per-token cost at all. See best AI apps for the wider free-vs-paid picture.

Features and ecosystem

ChatGPT is far broader — it is a full multimedia and agent platform; DeepSeek is a fast, free reasoning chat. This is the clearest reason to pay for ChatGPT.

ChatGPT does native image generation, Sora video, real-time voice, persistent memory, Deep Research, an autonomous Agent Mode, the Codex coding agent, over three million custom GPTs, Canvas, Projects and connectors — the deepest feature set and third-party ecosystem of any assistant. If you want one app that also makes images, edits video, talks to you and takes multi-step actions, ChatGPT is the obvious choice, and it has around a billion monthly users behind that ecosystem.

DeepSeek is deliberately narrow. It offers chat, the DeepThink reasoning toggle, an optional web-search toggle, file uploads (PDF, DOCX, TXT) and image understanding (vision input) — and that is essentially it. There is no image generation, no video, no conversational voice mode (voice is dictation only), no memory across chats, no custom bots and no agent mode. What it gives you instead is a frontier-adjacent reasoning model, free, with a 1M-token context — a capable chat box rather than a work platform. For its part, DeepSeek remains one of the world’s most-used AI assistants, reaching about 131.5 million monthly active users in January 2026 after its early-2025 breakout.

Privacy, data and availability

This is DeepSeek’s single biggest liability, and where ChatGPT is the safer default. The two apps handle your data in fundamentally different jurisdictions.

DeepSeek’s privacy policy states that consumer prompts, responses and account data are stored on servers in the People’s Republic of China. Under China’s 2017 National Intelligence Law, organisations can be compelled to assist state intelligence work, which is the basis for widespread regulatory concern. Italy, Australia, South Korea, Taiwan, India, the Czech Republic and more than 17 US states and federal agencies — including NASA and the US Navy — have banned or restricted the app, and Germany has asked Apple and Google to delist it. For many organisations the hosted DeepSeek app is simply off the table.

ChatGPT keeps consumer data in the US and is not subject to those government bans. Its defaults are not perfect: Free and Plus conversations may be used for training unless you opt out, the Free and Go tiers show ads in a growing number of markets, and a court in the New York Times copyright case has ordered OpenAI to retain and produce anonymised ChatGPT logs. But it holds SOC 2 Type 2 and ISO certifications, excludes training on Business and Enterprise tiers, and offers enterprise data-residency options. For anything genuinely sensitive, neither hosted consumer app is right — but DeepSeek gives you an escape hatch ChatGPT cannot: self-host the MIT-licensed weights to get the same model with none of the China data path, or use an EU-based app like Le Chat for managed privacy.

Choose DeepSeek if…

• You want frontier-adjacent AI for free — the full DeepSeek V4 model, DeepThink reasoning and a 1M-token context, with no paid tier and no ads.
• You want some of the cheapest API rates of any major lab, especially off-peak, or open weights you can self-host, fine-tune and run commercially under MIT.
• Your work is reasoning, maths and coding on a budget, and you are not handling sensitive or regulated data in the hosted app.

Choose ChatGPT if…

• You want the most capable assistant — it runs GPT-6 Astra, OpenAI’s flagship since 5 September 2026, which scores 53 on the independent Artificial Analysis Intelligence Index.
• You want breadth: image generation, Sora video, real-time voice, memory, Deep Research and autonomous agents, none of which DeepSeek has.
• You need US data handling and enterprise compliance rather than an app that stores data in China and is banned in several jurisdictions.

Frequently asked questions

Is DeepSeek or ChatGPT better?

It depends on what you value. DeepSeek is better for price and openness — it is free, runs the open-weight DeepSeek V4 with a 1M-token context, and can be self-hosted. ChatGPT is the more capable and complete assistant, running GPT-6 Astra on its paid tiers, with image generation, video, voice, memory and agents. For free, capable reasoning, choose DeepSeek; for the most powerful, feature-rich app with safer data handling, choose ChatGPT.

Is DeepSeek cheaper than ChatGPT?

Yes, by a wide margin. The DeepSeek app is completely free with no paid tier, and its API costs $0.66 / $1.98 per million tokens off-peak for V4-Pro (double at peak) — roughly 25 times cheaper on output off-peak than ChatGPT’s GPT-6 Astra flagship at $10 / $50 (about 13 times at peak), and about 10 times cheaper off-peak than GPT-5.6 Sol even at Sol’s promotional $4 / $20. ChatGPT has a free tier too, but it runs a lighter model and shows ads in a growing number of markets, and its flagship needs a paid plan starting at $20/month.

Is DeepSeek safe to use?

It is safe for everyday, non-sensitive tasks, but the hosted app stores data on servers in China, so it is not appropriate for confidential, personal or regulated information. Italy, Australia, South Korea and more than 17 US states and agencies have banned or restricted it. ChatGPT keeps data in the US and is the safer default; for the DeepSeek model without the China data path, self-host the MIT-licensed weights.

Which is better for coding, DeepSeek or ChatGPT?

ChatGPT’s flagship is stronger on the hardest coding: GPT-6 Astra scores 62 on the Artificial Analysis Coding Agent Index, level with Claude Fable 5.1, and GPT-5.6 Sol (64.6%) and GPT-5.5 (58.6%) both beat DeepSeek V4-Pro on the harder SWE-bench Pro (~55%). DeepSeek wins on cost — V4-Pro output is about 25 times cheaper than GPT-6 Astra’s off-peak (about 13 times at peak), which makes it the rational pick for high-volume or self-hosted coding agents. See best AI for coding.

Can DeepSeek replace ChatGPT?

For free reasoning, maths and coding, yes — many people use DeepSeek as their default for those tasks. But it cannot match ChatGPT’s breadth: DeepSeek has no image or video generation, no conversational voice mode, no memory and no agents. If your work spans media generation, voice and multi-step automation, ChatGPT remains the more complete single app.

Does DeepSeek generate images like ChatGPT?

No. DeepSeek can analyse images you upload, but it cannot create them, and it has no video generation. ChatGPT generates images natively and produces video with Sora on its paid tiers. If you need image or video generation, DeepSeek is not the tool.

Is DeepSeek V4 as good as ChatGPT’s GPT models?

Close on everyday tasks, behind on the hardest ones. On the earlier v4.1 scale of the independent Artificial Analysis Intelligence Index, DeepSeek V4-Pro scored 52, against 55 for GPT-5.5 and 59 for GPT-5.6 Sol; on the current v4.3 scale, ChatGPT’s flagship GPT-6 Astra scores 53, above Sol’s 47. NIST’s CAISI evaluation in May 2026 put V4 about eight months behind the US frontier. V4 is the best open-weight model for the money; ChatGPT’s flagship is the more capable model overall.