DeepSeek V4.1 Flash vs GPT-6 Astra: Four Real Builds, Full Cost and Time Breakdown

Disclaimer: deepseek.ai is an independent community site and is not affiliated with DeepSeek AI or OpenAI. The numbers on this page come from a single third-party creator test run through OpenRouter's paid API, not from a standardised benchmark suite and not from our own lab. Treat them as one data point, not as a measurement you can expect to reproduce exactly.

Most model comparisons stop at benchmark tables. This one didn't: an independent creator gave the exact same prompts to DeepSeek V4.1 Flash and to GPT-6 Astra across four very different builds, then logged the API cost, token consumption and wall-clock build time for every iteration.

The headline: DeepSeek finished the whole project for roughly $20 in API spend against roughly $118 for Astra — about six times cheaper — while taking almost three times as long (14h52m vs 5h30m).

The Test Setup

• Builds: an Age of Empires-style RTS replica, a 3D scroll-scrub animated website, a barber-shop booking app with a database backend, and a Blender truck animation.
• Access: paid API via OpenRouter for both models, so cost, tokens and build time could be measured per run.
• Judging criteria: output quality, functionality, API cost, build time, and how well each model absorbed follow-up feedback.
• Iterations: every build went through two to four rounds of re-prompting, so the totals include fixing, not just first drafts.

Headline Numbers: Whole Project

Read those four rows together and the pattern is clear. DeepSeek burned five times more tokens and made twice as many requests, yet still spent six times less money — because the per-token price is so much lower. The cost of that approach is time: many more internal checks, retries and self-corrections before it settles on a working version.

Build 1 — Age of Empires Replica

Both models produced a playable RTS: building houses and farms, training units, combat, and a real end-of-game condition when the town centre fell. Astra's first version looked noticeably better — cleaner graphics, a proper start menu, movement indicator lines, and a farm that villagers could actually tend. DeepSeek's first pass had a broken farm interaction, no tech evolution and no watchtower; all three were fixed on re-prompting, and V2 also added unit formations (line, box, flank, staggered) and correct defeat logic.

Both eventually implemented fog of war on request. Verdict in the test: Astra — mostly on visual quality and the four-hour wait on the DeepSeek side, not on functionality.

Build 2 — 3D Scroll-Scrub Website

This was a watch-brand landing page where a generated video is sliced into frames and scrubbed on scroll. Both struggled with frame pacing at first — DeepSeek block-deleted frames to reduce file size instead of dropping every second or third frame, which made the animation jump. By its fourth iteration the transition was smooth, hover images were correct and mobile spacing had improved, though alignment was still imperfect.

Astra reached a comparable result in fewer rounds and its hover-image consistency was better from the start. A large share of the elapsed time on both sides was simply waiting for image and video generation, not model reasoning. Verdict in the test: a tie — roughly six times cheaper with DeepSeek, roughly three times faster with Astra.

Build 3 — Barber Shop Booking App

The most "ordinary business software" test, and the most decisive. Both builds shipped a SQLite-backed booking flow, a private customer link for managing an appointment, a staff login, unavailability blocks, cancellation syncing to the backend, and correct double-booking prevention (the taken slot disappeared).

Astra's UI was more polished; the functionality was equivalent, and for the first time build times were comparable. At seven to eight times cheaper, the verdict in the test was DeepSeek. For a small local business tool, this is the shape of workload where the price gap matters most and the polish gap matters least.

Build 4 — Blender Truck Animation

The prompt asked for a truck crossing rough terrain with a camera pan around the body and under the chassis, showing suspension and drivetrain in as much detail as possible. Astra's mechanical detail was clearly stronger on the first attempt — tyre tread, wheel spokes, drivetrain — and on a follow-up it modelled a full engine bay with reservoirs, battery, bonnet struts and latch.

DeepSeek's model was less detailed but structurally correct, with visible suspension travel over the bumps. When both animations were pushed through a video model to create a photoreal render, the tester preferred DeepSeek's outback scene as usable B-roll. Verdict in the test: DeepSeek for B-roll, Astra for engineering-grade detail — at roughly nine to ten times the cost.

What the Results Actually Tell You

1. The gap is economic, not capability-shaped. Across all four builds both models eventually produced working software. What differed was polish on the first attempt and the price of getting there.
2. Astra converges faster; DeepSeek iterates cheaper. Astra's first version needed less debugging. DeepSeek reached the same place through more loops — which costs time you feel, and money you barely notice.
3. Time has a price too. If you bill clients per project, three hours saved can be worth more than $100 of API credit. If you're building for yourself in the evening, it usually isn't.
4. Media generation dominates elapsed time. On the website and Blender builds, most waiting was image and video rendering, not the language model.
5. Cheaper tokens change how you work. At DeepSeek prices, throwing a fifth iteration at a problem is a rounding error. That alone changes prompting behaviour.

How This Maps to Current DeepSeek Pricing

The test used a V4.1 Flash beta through a reseller, so the absolute figures won't match first-party rates. If you want to model your own spend against DeepSeek's own published rate card — including cache-hit pricing, which is where agentic loops get dramatically cheaper — use our DeepSeek pricing page and the cross-provider cost comparator on the homepage. For the model line-up itself, see DeepSeek V4 and V4-Flash.

Note also that V4.1 Flash was an expiring beta (the model string carried its own end date). Anything you build for production should target the generally available models documented in the DeepSeek API guide.

Which Should You Use?

• Solo builder, side project, tight budget: DeepSeek. The extra wait is the price of a six-fold discount.
• Agency shipping client work on deadline: Astra, with the API cost built into your quote. Speed is the product.
• Business tooling — bookings, CRUD, dashboards: DeepSeek. Same functionality, a fraction of the spend.
• Precision 3D or engineering-grade modelling: Astra's first-pass detail was materially better.
• Marketing B-roll and visual concepts: DeepSeek, then a strong video model on top.

Frequently Asked Questions

Is DeepSeek V4.1 Flash cheaper than GPT-6 Astra?

In this test, yes — about six times cheaper in total API spend ($20 vs $118) across four identical builds, despite consuming roughly five times more tokens.

Why did DeepSeek use five times more tokens but still cost less?

Because its per-token price is far lower. DeepSeek also ran more internal checks and self-corrections, which raised token counts and build time while keeping the bill small.

Which model was faster?

Astra, by a wide margin: 5h 30m against 14h 52m for the whole project. The largest single gap was the RTS build (47 minutes vs 4h 14m).

Did either model fail a build?

No. All four builds worked in both models after iteration. The differences were visual polish, first-attempt quality and how many rounds were needed.

Are these numbers official benchmarks?

No. They come from one independent creator's paid API runs, not a standardised suite, and V4.1 Flash was an expiring beta model. Use them as directional evidence, not as guaranteed results.

Can I reproduce this on DeepSeek's own API?

You can run the same four prompts against the currently available DeepSeek models, but the costs will differ from a reseller's. Model your spend against the published rate card on our pricing page first.