Let Me Speak Freely? A Study on the Impact of Format Restrictions on Performance of Large Language Models · HackerPapers discussions

Let Me Speak Freely? A Study on the Impact of Format Restrictions on Performance of Large Language Models — mentioned by jesdo

Mon, 26 Oct 2026 16:03:39 GMT

We are also interested in this and may focus on it in a future post. They are two different perspectives: (1) What is the overall quality of LLM+serving stack+harness, and (2) How close does the behavior of our setup match the first-party provider's? In this post, we focused on the latter. Moonshot AI, the creators of Kimi, recommend constrained decoding to be on by default, and also serve Kimi that way. This implies that it helps overall performance, though it does not provide numbers for it. We want to serve Kimi as recommended, and ran into the challenges described in the post. There is…

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Let Me Speak Freely? A Study on the Impact of Format Restrictions on Performance of Large Language Models — mentioned by martinald

Fri, 14 Aug 2026 14:48:29 GMT

Keep in mind all this kind of stuff can make the model less capable. If it has to think in "plain" English, it may well be squashing quality of code etc output. I'm not sure how true this is, but when using "forced" json output it def had a big drop off in quality - https://arxiv.org/html/2408.02442v3. I think you're better not fighting it with hacks like this and find a different model.

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Let Me Speak Freely? A Study on the Impact of Format Restrictions on Performance of Large Language Models — mentioned by tensegrist

Tue, 14 Jul 2026 18:02:55 GMT

things like that indeed tend to be fraught some relevant links https://arxiv.org/abs/2408.02442 https://arxiv.org/abs/2510.15061 https://arxiv.org/abs/2604.13006

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Let Me Speak Freely? A Study on the Impact of Format Restrictions on Performance of Large Language Models — mentioned by visarga

Tue, 23 Sep 2025 16:15:07 GMT

I was hoping to find some insights about why performance drops when using actual structured outputs. It's been a known problem. For example this paper "Let Me Speak Freely? A Study on the Impact of Format Restrictions on Performance of Large Language Models" says: > Surprisingly, we observe a significant decline in LLMs’ reasoning abilities under format restrictions. Furthermore, we find that stricter format constraints generally lead to greater performance degradation in reasoning tasks. https://arxiv.org/abs/2408.02442v1

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Let Me Speak Freely? A Study on the Impact of Format Restrictions on Performance of Large Language Models — mentioned by xiaofei_

Mon, 02 Sep 2024 01:02:58 GMT

I appreciate you taking the time to read the article and share your thoughts. Your arguments consider many perspectives and dimensions. Please allow me to address each point: > You’re comparing apples to oranges - structured output (a capability) with structured output + CoT (a technique), saying that structured output isn’t good for reasoning. Well, it’s not supposed to “reason,” and you didn’t apply CoT to it! The goal of our evaluation is to address the original OpenAI JSON mode statement: https://openai.com/index/introducing-structured-outputs-in-t... (see the section “Separating a final…

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Let Me Speak Freely? A Study on the Impact of Format Restrictions on Performance of Large Language Models — HN submission

Sat, 31 Aug 2024 09:15:37 GMT

A Study on the Impact of Format Restrictions on Performance of LLM

2 points; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Let Me Speak Freely? A Study on the Impact of Format Restrictions on Performance of Large Language Models — HN submission

Fri, 16 Aug 2024 10:33:00 GMT

A Study on the Impact of Format Restrictions on Performance of LLM

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Let Me Speak Freely? A Study on the Impact of Format Restrictions on Performance of Large Language Models — HN submission

Tue, 13 Aug 2024 12:49:36 GMT

Study on the Impact of Format Restrictions on Performance of LMM

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Let Me Speak Freely? A Study on the Impact of Format Restrictions on Performance of Large Language Models — HN submission

Wed, 07 Aug 2024 15:49:10 GMT

A Study on the Impact of Format Restrictions on Performance of LLMs

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Let Me Speak Freely? A Study on the Impact of Format Restrictions on Performance of Large Language Models — HN submission

Wed, 07 Aug 2024 01:15:13 GMT

A Study on the Impact of Structured Output on Performance of LLMs

2 points; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Let Me Speak Freely? A Study on the Impact of Format Restrictions on Performance of Large Language Models — mentioned by blackcat201

Wed, 07 Aug 2024 01:10:35 GMT

Do beware on some reasoning task, our recent work[0] actually found it may cause some performance degradation as well as possible reasoning weakening in JSON. I really hope they fix this in the latest GPT-4o version. [0] https://arxiv.org/abs/2408.02442

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