Ranked #10 Coding — AI That Writes Production Code
DeepSeek

DeepSeek-V4.1-Flash-1017

A cheap, open-weight coding agent that reads screenshots, holds a million tokens of context, and finishes repository tasks for about twenty cents each in DeepSeek's own cost chart. “Flash” is the tier, not a promise of small size.

Updated October 19, 2026 Coding AgentMultimodal InputOpen Weights
9.1out of 10
Official Website
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A cheap, open-weight coding agent that reads screenshots, holds a million tokens of context, and finishes repository tasks for about twenty cents each in DeepSeek's own cost chart. “Flash” is the tier, not a promise of small size.

Why It Wins

DeepSeek reports 77.0 on DeepSWE v1.1, ahead of the 74.0 it lists for Claude Opus 5 and the 73.0 for GPT-5.6 Sol, at unchanged prices of $0.15–$0.30 input and $0.60–$1.20 output per million tokens, depending on the hour. The weights are MIT-licensed.

Watch out

Every 1017 number is DeepSeek's own, and Opus 5 still leads its table on Terminal-Bench 4.0, ProgramBench and NL2Repo. Artificial Analysis has scored only the earlier September checkpoint, at 39 on its Intelligence Index, three points behind GLM-5.3-Flash.

01

What It Actually Is

Picture two tradespeople. One is a master who solves the hardest job in the building, but you pay by the hour and the meter runs fast. The other is nearly as handy on ordinary work, finishes sooner, talks less, and charges far less. For a repair queue with a thousand tickets, you hire the second one for most of them and keep the master on speed dial. DeepSeek-V4.1-Flash-1017 is the second tradesperson.

On October 17, 2026 DeepSeek swapped this version into its website, app and API under the same deepseek-flash name, with prices untouched. The standard rate is $0.15 per million input tokens and $0.60 per million output tokens; during weekday peak windows (01:00–04:00 and 06:00–10:00 UTC) it doubles to $0.30 and $1.20, so the practical range is $0.15–$0.30 in and $0.60–$1.20 out. The company calls it a minor update to September’s V4.1 Flash. The changes it lists are better reasoning, coding and visual scores, plus shorter outputs and faster tasks. Cheaper cost per task comes from that last pair. A model that reaches the same fix in fewer tokens is cheaper without any change to the price list.

Here is what that looks like in DeepSeek’s numbers. On DeepSWE v1.1, a test where the model must repair real software projects, it reports 77.0, up from 74.2. It lists Claude Opus 5 at 74.0 and GPT-5.6 Sol at 73.0. On the much harder Terminal-Bench 4.0 it reports 42.3, up from 31.2 and above the 37.9 it lists for GLM-5.3, yet far behind Opus 5’s 51.8. Its cost chart puts the top setting at about 77% success for roughly twenty cents a task; the chart does not say whether that assumes standard or peak rates, so assume the lower figure could roughly double in peak hours. Every one of those figures is DeepSeek’s, produced with harnesses DeepSeek selected, and the Terminal-Bench run used the Claude Code harness while DeepSWE used a different one. A good reader treats the table as a strong claim to confirm, not as a verdict.

The independent record is thinner. Artificial Analysis has scored the September V4.1 Flash, which has 552 billion total parameters and about 16 billion active per token: 39 on its Intelligence Index, version 4.3.2. On that same version GLM-5.3-Flash scores 42. So on broad intelligence, measured by a third party, DeepSeek’s Flash trailed its rival before this update. DeepSeek’s update targets agent work, where its own tables show the largest gains, and that is where independent testing should look next. (Earlier GLM-5.3 reviews on this site quote a higher index figure from an older version of the scale; scores from different versions cannot be compared.)

The model also sees. It accepts images, which lets a front-end agent compare a rendered page with the intended design instead of reasoning from code alone, and it offers a 1M-token context with up to 384K tokens of output. Weights are on Hugging Face under the MIT license. The checkpoint is roughly 763 billion parameters in storage, though, so self-hosting is a datacenter decision rather than a laptop one. That is why we cover it for coding as a hosted API and review its private-hosting side in Local / Private AI.

Two practical notes. DeepSeek recommends its own DeepSeek Harness, version 0.2.1-rc.1 or later, and says it also tuned for Tencent’s CodeBuddy and WorkBuddy, so results in other agent frameworks may differ. And its new Search and Fetch APIs, which cost $0.75 per thousand calls, are free through certain server-side tools only until October 31, 2026, so budget for them afterwards.

The sensible plan is a division of labor. Let DeepSeek-V4.1-Flash-1017 work through the long queue of routine repairs, run the tests, and retry cheaply. Send the few problems that decide a release, such as deep terminal sessions and tangled migrations, to a stronger model. Then check the independent scores once they exist, because they will tell us whether this price-to-performance claim survives contact with someone else’s test.

02

Strengths and honest limitations

Key Strengths

  • Repository repair at a bargain price: DeepSeek’s cost-versus-success chart puts max effort at roughly 77% success for about $0.20 per task, against roughly 75% for about $0.65 on GPT-6.1 Sol at high effort. Those are chart readings from the vendor, but the gap is large enough to matter for agents that run all day.
  • Shorter answers, same price: The October 17 update cut output length and task time without touching the price list. Fewer output tokens is the cheapest improvement a coding agent can make, because output tokens cost four times as much as input. Prices are low at any hour: $0.15 input and $0.60 output per million tokens at the standard rate, $0.30 and $1.20 during peak windows, and DeepSeek’s cached-input rate is $0.003 off-peak.
  • Screenshots belong in the loop: The model accepts images, so a front-end agent can look at the broken page instead of guessing from the code. DeepSeek reports 92.5 on BabyVision and 83.0 on Chartography, both with tools.
  • Open weights and plain licensing: MIT weights mean a company can host the model itself, inspect it, and modify it. The 1M-token context and 384K maximum output suit whole-repository work.

Honest Limitations

  • No independent score for this checkpoint: DeepSWE, Terminal-Bench 4.0, Automation-Bench, Apex and the rest come from DeepSeek’s model card, run with harnesses DeepSeek chose. Artificial Analysis measured the September V4.1 Flash at 39, below GLM-5.3-Flash at 42 on the same index version; the 1017 update may close that gap, but nobody independent has shown it yet.
  • Behind Opus 5 on the hardest work: In DeepSeek’s own table Opus 5 scores 51.8 on Terminal-Bench 4.0 against 42.3, 37.0 against 29.1 on ProgramBench, and 56.3 against 42.6 on Humanity’s Last Exam. Long terminal jobs and messy knowledge work still favor the closed frontier.
  • Peak pricing doubles the bill: The standard rate applies on weekends and on weekdays outside two windows, 01:00–04:00 and 06:00–10:00 UTC, when every rate doubles. That is seven of 24 weekday hours, and it covers the Asian and European working morning. A team working those hours should budget $0.30 input and $1.20 output; one that can queue agent jobs for evenings and weekends gets the lower rate. GLM-5.3-Flash’s list price has no peak tier ($0.15 and $0.50), so at peak the output price is 2.4 times higher than its rival’s. DeepSeek also tuned the model for its own DeepSeek Harness and recommends version 0.2.1-rc.1 or later.
  • Self-hosting is a cluster project: The checkpoint is about 763 billion parameters, so running it yourself takes hundreds of gigabytes of fast memory even though only a fraction of the weights fire for each token. For most teams the hosted API is the realistic route.
03

Benchmark Snapshot

DeepSWE v1.1 — 77.0 (DeepSeek run, Mini-SWE harness)

Up from 74.2 for the September checkpoint and ahead of the 73.0 DeepSeek lists for GPT-5.6 Sol. A vendor-chosen harness can swing a result by several points, so treat the gap over rivals as a lead to verify.

Terminal-Bench 4.0 — 42.3 (DeepSeek run, Claude Code harness)

Up from 31.2, and above the 37.9 DeepSeek lists for GLM-5.3, but well under Opus 5 at 51.8. This is the much harder 4.0 edition; do not compare it with Terminal-Bench 2.1 scores elsewhere on this site.

Automation-Bench 60.5 and Agents’ Last Exam 35.4 (DeepSeek run)

Both are the highest numbers in DeepSeek's comparison table, which is evidence for multi-step agent work rather than a final ranking.

Artificial Analysis Intelligence Index — 39 (September V4.1 Flash, v4.3.2)

Independent, but for the checkpoint before this update. The same index lists GLM-5.3-Flash at 42 and the September model at about $0.49 per index task on its listed API price.

04

The Verdict

DeepSeek-V4.1-Flash-1017 is for teams that run coding agents at high volume and care most about cost per finished task: repository fixes, test-and-retry loops, and screenshot-led front-end work. It replaces GLM-5.3-Flash in Coding with a 9.1, just below GLM-5.3-Flash’s old 9.2, because independent evidence stops at the earlier September checkpoint while DeepSeek’s own 1017 tables are strong. Use Claude Opus 5.5 or GPT-6 Astra for the hardest terminal jobs, and revisit this score when an independent test of the 1017 weights lands.

05

Frequently Asked Questions