GPT-5 Drops Today: We Re-Ran Our 9 Production Workflows on It (And One Already Got Cheaper)
GPT-5 launched today, August 7, 2025. We re-ran our 9 live client workflows on it the same afternoon. The cost-per-task chart, which 3 we switched immediately, the 4 we kept on GPT-4o-mini, and why.
Hrishikesh Baidya
August 7, 202512 min read
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OpenAI released GPT-5 today, August 7, 2025. Instead of writing a hot take, we did what we tell clients to do: we re-ran our 9 live production workflows on it the same afternoon and measured. One workflow — invoice-field extraction for a procurement client — got both cheaper and more accurate, so we switched it before dinner. Three others we moved. Four we deliberately kept on gpt-4o-mini. Here's the cost-per-task data and the decision behind each call.
$1.25
GPT-5 Input / 1M Tokens
$10
GPT-5 Output / 1M Tokens
400K
GPT-5 Context Window
3 of 9
Workflows We Switched
## The 60-Word Answer
GPT-5 launched today at $1.25 per 1M input tokens and $10 per 1M output, with a 400K context window. The cheaper tiers — gpt-5-mini ($0.25/$2) and gpt-5-nano ($0.05/$0.40) — matter more for production than the flagship. We moved 3 of our 9 workflows: one to gpt-5-mini for a real cost drop, two to GPT-5 for accuracy. We kept 4 on gpt-4o-mini where it was already good enough.
## Why This Matters Today
GPT-5 shipped today across ChatGPT and the API. The headline that actually changes our cost math isn't the flagship — it's the family. GPT-5 comes in three API sizes: gpt-5, gpt-5-mini, and gpt-5-nano, all with a 400K-token context window (per OpenAI's pricing page). For us, the question on launch day is never "is it smarter" — it's "does it change the cost-per-task on a workflow we're already running, or make one we'd parked viable." So we measured.
## The Cost-Per-Task Chart
We price our automations per task, not per token, because that's how clients think. Here's the per-task cost for four representative workflows, before and after the GPT-5 switch decision. The invoice-extraction workflow is the one that got cheaper — moving from gpt-4o-mini to gpt-5-mini cut errors enough that we removed a human review step, which is where the real saving came from.
## The 3 We Switched (and Why)
🧾
Invoice extraction → gpt-5-mini
Field accuracy on messy vendor PDFs rose enough to drop the human spot-check on 70% of invoices. Net cost per task fell from ₹2.10 to ₹1.40. The model upgrade paid for itself by removing labour, not tokens.
📄
Contract clause review → gpt-5
Long contracts now fit in the 400K window without splitting. Fewer chunks meant fewer stitched-together errors. Per-task cost rose in tokens but fell in re-work. We moved it to the flagship.
🔀
Multi-step agent → gpt-5
A research-and-summarise agent that chained 6 tool calls. GPT-5's stronger tool-routing cut a recurring loop-and-retry failure we'd been patching around. Reliability, not price, drove this one.
⚖️
The decision rule
We switch when the new model removes a human step, fits a context that used to need chunking, or kills a reliability bug. We do NOT switch for benchmark bragging rights.
## The 4 We Kept on GPT-4o-Mini
This is the unfashionable half of launch day. Four workflows stayed exactly where they were, and that was the right call.
Support reply drafting — gpt-4o-mini already wrote good first-draft replies. GPT-5 wrote marginally better ones at 4–8x the cost. Not worth it for a draft a human edits anyway.
Lead enrichment — a structured extraction task the cheap model nails. Upgrading would have raised cost with zero accuracy gain.
FAQ classification — routing a message to one of 12 buckets. A small model's job. GPT-5 here is using a sledgehammer on a thumbtack.
Tag suggestion — low-stakes, high-volume, error-tolerant. The cheapest model that works is the right model.
The rule we live by: the best model for a production workflow is the cheapest one that clears your accuracy bar — not the newest one on the leaderboard. Launch day is for re-checking the bar, not chasing the headline.
## How We Re-Ran Everything in One Afternoon
The reason we could measure on launch day, not launch month, is that every workflow is built to swap models with a one-line config change. If yours aren't, that's the real lesson here.
1
Model name is config, never hardcoded
Every workflow reads MODEL from an env var or a settings table. Switching to GPT-5 is a value change, not a code change. This alone made the afternoon possible.
2
A golden eval set per workflow
Each workflow has 20–50 saved input/output pairs with known-correct answers. We re-ran them on GPT-5 and diffed accuracy and cost against the recorded baseline. No vibes, just numbers.
3
Shadow-run before promoting
For the 3 we switched, we ran GPT-5 in shadow mode on live traffic for 48 hours — logging its output alongside the old model without showing it to users — before flipping the flag.
## The Wrong Reactions We're Seeing Today
Wrong reaction 1: "Switch everything to GPT-5." Most production workflows are classification, extraction, or routing — tasks a cheap model already does well. Blanket-upgrading multiplies your bill for accuracy you can't measure a gain from.
Wrong reaction 2: "GPT-5 is here, so our current bot is obsolete." A working bot that clears its accuracy bar is not obsolete because a new model exists. Obsolescence is a measured accuracy gap, not a press release.
Wrong reaction 3: "Ignore it, our stack is fine." The opposite error. The gpt-5-mini tier genuinely changed the math on one of our workflows. You don't have to switch — but you do have to re-measure, or you're guessing.
## Our Take
GPT-5 is a real step up on reasoning and long-context work, and the mini/nano tiers are where most teams will feel it. But launch day is an audit trigger, not a migration mandate. The teams that win today aren't the ones who switched fastest — they're the ones who could measure fastest, because their workflows treat the model as swappable config with a golden eval set behind it.
This is the same discipline our founder Vivek Singh writes about on model churn: build for the model to change, because it will, every few months. Our AI automation team ships every client workflow with model-as-config and an eval set from day one — see how we re-ran our 9 most-used n8n workflows for 2025 and how we handled the Claude Haiku 4.5 launch the same way.
Community pulse: the launch-day Hacker News thread split predictably between "it's a huge leap" and "incremental, mostly cheaper" — both true depending on whether your work is reasoning-heavy or routing-heavy.
## Frequently Asked Questions
### How much does GPT-5 cost via the API?
At launch on August 7, 2025, GPT-5 is $1.25 per 1M input tokens and $10 per 1M output tokens. The cheaper tiers are gpt-5-mini ($0.25 / $2.00) and gpt-5-nano ($0.05 / $0.40). All three offer a 400K-token context window per OpenAI's pricing page.
### Should I switch all my workflows to GPT-5?
No. Switch only where the new model removes a human review step, fits content that used to need chunking, or fixes a reliability bug. Classification, routing, and simple extraction tasks usually run fine and cheaper on a smaller model. Re-measure each workflow before deciding.
### What's the difference between gpt-5, gpt-5-mini, and gpt-5-nano?
They trade capability for cost. gpt-5 is the most capable and most expensive; gpt-5-mini is a mid tier that often hits the sweet spot for production; gpt-5-nano is the cheapest for high-volume, simpler tasks. All share the 400K context window at launch.
### How do I test a new model on my own workflows quickly?
Keep the model name in config, not hardcoded, and maintain a golden eval set of 20–50 known-correct input/output pairs per workflow. On launch day you change one config value, re-run the eval, and compare accuracy and cost against your recorded baseline.
### Did GPT-5 make any workflow cheaper for you?
Yes — invoice-field extraction. Moving from gpt-4o-mini to gpt-5-mini raised field accuracy enough that we dropped the human spot-check on 70% of invoices. Net cost per task fell from ₹2.10 to ₹1.40, with the saving coming from removed labour rather than tokens.
### Is a working chatbot built on an older model now obsolete?
Not because a new model launched. A bot is obsolete only when you can measure an accuracy or cost gap that matters to your users. Treat a launch as a reason to re-run your eval set, not as automatic proof your current build needs replacing.
Want your AI workflows built to survive the next model launch?
We build automations for Indian SMBs with the model as swappable config and a golden eval set behind every workflow — so the next launch is a 1-line change, not a rewrite. Typical engagement: ₹80k–₹2L. Suitable if you're already running LLM workflows and want them launch-proof. First call is technical, with the engineer who'd lead it.
As Hrishikesh, our CTO, said when the model dropped: "Don't ask if it's better. Ask which of your bills it changes — and have the eval set to answer by tonight."