Exclusive: Here's How Much OpenAI Spends On Inference and Its Revenue Share With Microsoft
We recorded 10 claims from this post. 7 were checked against evidence. 3 can’t be checked. 7 more are held. Read the post at its source.
Claims from this post (10)
In the order they appear in the post. Each quotation is the speaker’s words in this post. A label such as “Supported” or “Can’t be checked” is the claim’s current assessment; its page has the evidence and the reasons.
Assessment: UnresolvedSaid
“According to the documents viewed by this newsletter, OpenAI spent $5.02 billion on inference alone with Microsoft Azure in the first half of Calendar Year CY2025.”
What we tested: OpenAI spent $5.02 billion on inference with Microsoft Azure in the first half of 2025.
Assessment: UnresolvedSaid
“This is a pattern that has continued through the end of September. By that point in CY2025 — three months later — OpenAI had spent $8.67 billion on inference.”
What we tested: OpenAI spent $8.67 billion on inference with Azure from January through September 2025.
Assessment: UnresolvedSaid
“According to the documents, Microsoft received $493.8 million in revenue share payments in CY2024 from OpenAI — implying revenues for CY2024 of at least $2.469 billion, or around $1.23 billion less than the $3.7 billion that has been previously reported.”
What we tested: Microsoft received $493.8M in revenue share from OpenAI in 2024, implying OpenAI 2024 revenue of at least $2.469B, about $1.23B below reported figures.
Assessment: UnresolvedSaid
“Through September, Microsoft’s revenue share payments totalled $865.9 million, implying OpenAI’s revenues are at least $4.329 billion.”
What we tested: Microsoft's revenue share payments through September 2025 totalled $865.9M, implying OpenAI revenue of at least $4.329B.
Assessment: UnresolvedSaid
“Similarly, for the first half of CY2025, Microsoft received $454.7 million as part of its revenue share agreement, implying OpenAI’s revenues for that six-month period were at least $2.273 billion, or around $2 billion less than the $4.3 billion previously reported.”
What we tested: Microsoft's $454.7M revenue share in H1 2025 implies OpenAI revenue of at least $2.273B, about $2B below the reported $4.3B.
Assessment: Can’t be checkedSaid
“Based on the information in this piece, OpenAI’s costs and revenues are potentially dramatically different to what we believed.”
What we tested: OpenAI's costs and revenues are potentially dramatically different from what was publicly believed.
Assessment: UnresolvedSaid
“OpenAI’s inference spend with Microsoft Azure between CY2024 and Q3 CY2025 was $12.43 billion. That is an astonishing figure, one that dramatically dwarfs any and all reporting, which, based on my analysis, suggested that OpenAI spent $2 billion on inference in 2024 and $2.5 billion through H1 CY2025. In other words, inference costs are nearly triple that reported elsewhere.”
What we tested: OpenAI spent $12.43B on Azure inference from 2024 through Q3 2025, nearly triple what was reported elsewhere.
Assessment: Can’t be checkedSaid
“Based on these numbers, it appears that OpenAI may be the single-most cash intensive startup of all time, and that the cost of running large language models may not be something that can be supported by revenues.”
What we tested: OpenAI may be the most cash-intensive startup of all time.
Assessment: Can’t be checkedSaid
“Based on these numbers, it appears that OpenAI may be the single-most cash intensive startup of all time, and that the cost of running large language models may not be something that can be supported by revenues.”
What we tested: The cost of running large language models may not be supportable by revenues.
Assessment: UnresolvedSaid
“I also cannot reconcile these numbers with the reporting that OpenAI will have a cash burn of $9 billion in CY2025. On inference alone, OpenAI has already spent $8.67 billion through Q3 CY2025.”
What we tested: Zitron cannot reconcile the documents' numbers with reporting that OpenAI will have a $9 billion cash burn in CY2025, given that OpenAI had already spent $8.67 billion on inference alone through Q3 CY2025.
Held from this post (7)
These records did not pass every check, so nothing about them is published. Held is not a finding.
- The criteria are ambiguous. Our reading, not assessed: Zitron believes that if inference costs OpenAI this much, it costs this much for any generative AI firm running on OpenAI's models, and that if it does not, OpenAI's costs are dramatically higher than the prices it charges customers, which makes him wonder whether price increases could be necessary for OpenAI to make more money or lose less.
- The two reviews reached different assessments. Our reading, not assessed: Zitron cannot see a path for OpenAI to hit its projected $13 billion in revenue by the end of 2025, nor any basis for Sam Altman's statement that OpenAI will make 'well more' than $13 billion this year.
- The two reviews read the claim differently
- The two reviews read the claim differently
- The criteria are ambiguous. Our reading, not assessed: Based on OpenAI's reported revenues of $3.7 billion in CY2024 and $4.3 billion in the first half of CY2025, it seems that OpenAI's inference costs easily eclipsed its revenues.
- The criteria are ambiguous. Our reading, not assessed: Even at reported revenue levels, OpenAI's Azure inference spend consumes its revenue and appears to scale linearly above it.
- The two reviews read the claim differently