What if you want Claude
to speed things up and get you an answer back faster? Well Claude has a mode for that, Fast
mode! But there is going to be a costs!
What is fast mode?
The fast mode delivers
up to 2.5 faster output token generation while using the exact same model,
weights, intelligence and capabilities as the standard version. Long story short its just faster, simple as
that.
It is only available in Opus
If we are looking at
token cost via the API https://claude.com/pricing#api [1]
If we look at Opus we
can see that input is $5/MTok and output is $25/MTok
If we look at fast
pricing https://platform.claude.com/docs/en/about-claude/pricing#fast-mode-pricing
We can see that Opus 4.6/4.7 costs $30/Mtok for input and $150/MTok for output. But for Opus 4.8 its 3x cheaper $10/MTok for input and $50/MTok for output.
So…. If you are using
Opus 4.6/4.7 you are going to spend 6X for fast and for Opus 4.8 you will spend
2x for fast
Let’s test this
Let me see if Claude will track time of a prompt
Run this prompt
|
> While I am in this session when you
complete a task after a prompt post how long it took to complete in seconds |
|
> I am going to be running some speed
test. If I ask you to do the same
thing over and over again do not use any previous learned information just
start fresh. Do not read any previously created files just replace them |
Let’s give it something to do
|
> Create a complete Python class called `TaskManager` with the following features: - Add a
task (with title, description, due date) Use
proper type hints, docstrings, and include example usage at the bottom. Make
it production-quality code. |
OK … it asked for some permissions but it took 62 seconds.
Let me rerun it
Run 1 : 26 seconds
Run 2: 26 seconds
Run 3: 25 seconds
Run 4: 31 seconds
Now lets switch to fast mode
|
>
/fast on |
It gives you a price warning
OK let’s try it
|
> Create a complete Python class called `TaskManager` with the following features: - Add a
task (with title, description, due date) Use
proper type hints, docstrings, and include example usage at the bottom. Make
it production-quality code. |
Run 1: 26 seconds
Run 2: 26 seconds
Run 3: 26 seconds
Run 4: 25 seconds
OK…
No real difference in this example.
Asking AI why? It came back with this.
|
Fast
Mode primarily speeds up output token generation rate (how fast tokens
stream out once Claude starts writing). It does not significantly
speed up:
Your
test prompt (TaskManager class) is medium-length output. For prompts
like this, a lot of the total time is spent in reasoning rather than pure
token generation. That's why normal and fast mode ended up very close (mostly
in the 25–26 second range). This is
a common observation from people who have tested it. |
Second example
Let’s try a second example
Turn fast off
|
>
/fast off |
|
> Build a full React + TypeScript dashboard for a project management tool. Include: -
Sidebar navigation Generate
all the main components and files. |
First run: 210 seconds
Second run : 171 seconds
Now turn fast mode on and retry
Oh! It got turned off on me.
How odd since I am paying per token and not on a monthly plan
OK waiting 30 min then trying this again.
Looking at Handle rate limits https://code.claude.com/docs/en/fast-mode#handle-rate-limits [2]
Looks like if you are on a sub plan, you have to pay extra,
and if you run out of credits it will fall back to normal speed (not my case).
But for everyone there is a rate limit pool, which I can’t seem to find… So I guess I just wait 30 min.
First run: 180 seconds
Second run: 316 seconds
OK so… no real improvements maybe even it was worse.
Subscription plans
OK what about subscription plans? Looking at their web site https://code.claude.com/docs/en/fast-mode [3]
It looks like you can use /fast mode but you will pay extra for it.
|
For Claude Code users on subscription plans
(Pro/Max/Team/Enterprise), fast mode is available via usage credits only and
not included in the subscription rate limits. |
So you can use it but you are gonna pay extra.
Final Thoughts
I do not see any real reason to use this at this time, maybe that will change in the future. I could see a value in paying 2-3x more for getting 2-3x overall speed up but its just not there yet. Also with limits on when and how I can use it now… When I need it would it even be available.
Give it a year or two and we will see how this turns out.
References
[1] Claude Pricing
https://claude.com/pricing#api
Accessed 05/2026
[2] Handle rate limits
https://code.claude.com/docs/en/fast-mode#handle-rate-limits
Accessed 05/2026
[3] Speed up responses with fast
mode
https://code.claude.com/docs/en/fast-mode
Accessed 05/2026
No comments:
Post a Comment