Which is cheaper, Kimi K3 or Qwen3.8-Flash?

Qwen3.8-Flash is cheaper: $0.15 per million tokens read and $0.47 per million written, against $3 and $15 on Kimi K3. On a mix of 3 tokens read for each 1 written, Kimi K3 costs 26 times as much.

Which is better, Kimi K3 or Qwen3.8-Flash?

Kimi K3 scores 157 on the Epoch Capabilities Index, an independent score from Epoch AI that combines over 50 benchmarks (GPT-5 is 150). Qwen3.8-Flash has no independent score yet, so the only fair test is to run the same 10 tasks on both.

What does a support bot cost a month on Kimi K3 and Qwen3.8-Flash?

At 2,000 replies a day, each reading 4,000 tokens (50 percent of them from cache) and writing 300, it costs $666 a month on Kimi K3 and $28.38 on Qwen3.8-Flash: Kimi K3 costs 23 times as much for this job.

What does an AI agent task cost on Kimi K3 and Qwen3.8-Flash?

One 40-turn task that reads 2,800,000 tokens in all, 90 percent of them from cache, and writes 40,000, costs $2.20 on Kimi K3 and 10 cents on Qwen3.8-Flash. At 10 tasks a day that is $659 and $30.34 a month.

Does the same text take the same number of tokens on Kimi K3 and Qwen3.8-Flash?

No. Our lesson "How AI writes", 1,700 words long, is 2,055 tokens on Kimi K3 and about 2,100 on Qwen3.8-Flash. Each maker cuts text its own way, and every extra token is paid for at the model's price.

Can I pay less on Kimi K3 and Qwen3.8-Flash for work that can wait?

Not with a batch price: neither maker's price page lists one for these models. A cache still lowers the price of text the model reads again.

Kimi K3 vs Qwen3.8-Flash

Qwen3.8-Flash is the cheaper of the 2: for the same tokens, 3 read for each 1 written, Kimi K3 costs 26 times as much. Below are both price lists, what 8 everyday jobs cost a month on each, and how many tokens the same text takes on each, which can change the answer.

Price your own job Compare 2 other models

For the same tokens: Qwen3.8-Flash is cheaper; Kimi K3 costs 26 times as much
Cheaper to read: Qwen3.8-Flash, $0.15 against $3
Cheaper to write: Qwen3.8-Flash, $0.47 against $15
Scores higher: Not known, Qwen3.8-Flash has no independent score yet
Larger window: Not listed for Qwen3.8-Flash

Price per million tokens, side by side

In US dollars, as each maker prints them. The better figure in each row is green.

	Kimi K3Moonshot AI	Qwen3.8-FlashAlibaba
InputTokens the model reads	$3	$0.15
Cached inputRead again from the cache	$0.30	$0.016
Cache writePutting text in the cache	$3	Not listed
OutputTokens it writes, thinking included	$15	$0.47
Blend 3:13 tokens read for each 1 written	$6	$0.23
Batch inputAnswers collected later	Not listed	Not listed
Batch output	Not listed	Not listed
Context windowTokens it holds at once	1.05M	Not listed
Capability scoreEpoch Capabilities Index; GPT-5 is 150	157	Not listed
Longest answerTokens it writes in 1 reply	Not listed	Not listed

The same text, counted by each maker

A price per token means little until you know how many tokens your text is. Here is our lesson How AI writes, about 1,700 words of English, counted the way each maker counts it, and what it costs to send it once.

Kimi K3
2,055 tokens
Sent once: 0.62 cents at $3 per million
Counted with the tokenizer Moonshot AI publishes with Kimi K3, the model its API serves.
Qwen3.8-Flash
about 2,100 tokens
Sent once: 0.032 cents at $0.15 per million
Counted with the tokenizer Alibaba publishes with its open Qwen3.8 models. Alibaba does not say its API models use the same one, so the count is marked as about.

What 8 everyday jobs cost a month on each

Each job at its usual number of runs a day, for 30 days, at the standard price. The cheaper of the 2 is green; open any job in the calculator to change it.

Job	Kimi K3	Qwen3.8-Flash	Difference
A chat question300 in, 500 out, 100 a day	$25.200.84 cents a run	84 cents0.028 cents a run	30 times
A hard question, with thinking300 in, 1,400 out, 100 a day	$65.702.2 cents a run	$2.110.07 cents a run	31 times
A long report, summarised60,000 in, 2,000 out, 20 a day	$12621 cents a run	$5.960.99 cents a run	21 times
A 40-turn agent task2,800,000 in, 40,000 out, 10 a day	$659$2.20 a run	$30.3410 cents a run	22 times
A support bot's reply4,000 in, 300 out, 2,000 a day	$6661.1 cents a run	$28.380.047 cents a run	23 times
Sort a message into a category250 in, 5 out, 50,000 a day	$1,2380.083 cents a run	$59.770.004 cents a run	21 times
Read an invoice into fields1,500 in, 250 out, 1,000 a day	$2480.83 cents a run	$10.270.034 cents a run	24 times
Review a pull request25,000 in, 4,500 out, 50 a day	$21414 cents a run	$8.800.59 cents a run	24 times

Your own job on both

Start from a job, then set its size, how often it runs and whether the answers can wait. Both bills follow every change.

Start from a job

A short question and a few paragraphs back.

Read in 1 run

tokens

about 230 words

Read again from cache

Instructions or documents the model has read before cost far less the second time.

Written in 1 run, thinking included

tokens

about 380 words

Runs a day

A month of this job

Kimi K3$25.20
0.84 cents a run
Qwen3.8-Flash84 cents
0.028 cents a run

Qwen3.8-Flash saves $24.36 a month; Kimi K3 costs 30 times as much.

This job on every model

Why the price per token is only the start

Every maker prints 2 main prices: one for the tokens a model reads (input) and one for the tokens it writes (output). On most current models writing costs 3 to 5 times as much as reading, so which model is cheaper can depend on the job. A job that reads a long document and writes a line pays mostly the input price; a chat that writes paragraphs pays mostly the output price. That is why each comparison prices 8 jobs and not one figure.

The same text is not the same number of tokens on every model. Each maker cuts text its own way, and Anthropic says its models from Claude 4.7 on produce about 30 percent more tokens for the same text than earlier ones. A model with the lower price per token can still send the larger bill, so each comparison counts one of our lessons the way both makers count it.

Discounts change the order too. Work that can wait costs half on a batch at the makers that offer one, and text read again from a cache costs a quarter of the input price or less on every current model here. The price table on each comparison shows who offers what.

Thinking is billed as output, and models differ in how much they think and how long they answer. A price list cannot show that. Before you switch, run the same 10 tasks on both models and compare the bills.

Questions

Which is cheaper, Kimi K3 or Qwen3.8-Flash?: Qwen3.8-Flash is cheaper: $0.15 per million tokens read and $0.47 per million written, against $3 and $15 on Kimi K3. On a mix of 3 tokens read for each 1 written, Kimi K3 costs 26 times as much.
Which is better, Kimi K3 or Qwen3.8-Flash?: Kimi K3 scores 157 on the Epoch Capabilities Index, an independent score from Epoch AI that combines over 50 benchmarks (GPT-5 is 150). Qwen3.8-Flash has no independent score yet, so the only fair test is to run the same 10 tasks on both.
What does a support bot cost a month on Kimi K3 and Qwen3.8-Flash?: At 2,000 replies a day, each reading 4,000 tokens (50 percent of them from cache) and writing 300, it costs $666 a month on Kimi K3 and $28.38 on Qwen3.8-Flash: Kimi K3 costs 23 times as much for this job.
What does an AI agent task cost on Kimi K3 and Qwen3.8-Flash?: One 40-turn task that reads 2,800,000 tokens in all, 90 percent of them from cache, and writes 40,000, costs $2.20 on Kimi K3 and 10 cents on Qwen3.8-Flash. At 10 tasks a day that is $659 and $30.34 a month.
Does the same text take the same number of tokens on Kimi K3 and Qwen3.8-Flash?: No. Our lesson "How AI writes", 1,700 words long, is 2,055 tokens on Kimi K3 and about 2,100 on Qwen3.8-Flash. Each maker cuts text its own way, and every extra token is paid for at the model's price.
Can I pay less on Kimi K3 and Qwen3.8-Flash for work that can wait?: Not with a batch price: neither maker's price page lists one for these models. A cache still lowers the price of text the model reads again.

Sources