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arXiv:2501.00663cs.LG

Titans: Learning to Memorize at Test Time

Ali Behrouz, Peilin Zhong, Vahab Mirrokni

Abstract

Over more than a decade there has been an extensive research effort on how to effectively utilize recurrent models and attention. While recurrent models aim to compress the data into a fixed-size memory (called hidden state), attention allows attending to the entire context window, capturing the direct dependencies of all tokens. This more accurate modeling of dependencies, however, comes with a quadratic cost, limiting the model to a fixed-length context. We present a new neural long-term memory module that learns to memorize historical context and helps attention to attend to the current context while utilizing long past information. We show that this neural memory has the advantage of fast parallelizable training while maintaining a fast inference. From a memory perspective, we argue that attention due to its limited context but accurate dependency modeling performs as a short-term memory, while neural memory due to its ability to memorize the data, acts as a long-term, more persistent, memory. Based on these two modules, we introduce a new family of architectures, called Titans, and present three variants to address how one can effectively incorporate memory into this architecture. Our experimental results on language modeling, common-sense reasoning, genomics, and time series tasks show that Titans are more effective than Transformers and recent modern linear recurrent models. They further can effectively scale to larger than 2M context window size with higher accuracy in needle-in-haystack tasks compared to baselines.

arXiv comments
Journal reference
DOI
Subjects
cs.LGMachine Learning cs.AIArtificial Intelligence cs.CLComputation and Language

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Linked by 15 identifiable commenters in 15 comments across 11 threads, from Jan 2025 to Apr 2026. Found in 3 HN submissions from Jan 2025 to Jan 2025. Open submission discussions.

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Discussed in comments11 threads

    • don't miss the (formerly over-hyped) Google Research's Titans+Atlas thread, they are quite inspiring and informative on the subject; even if I don't think they released anything (open, at least) as a follow-up to their research. https://arxiv.org/abs/2501.00663…

      carlovalentiView on HNParent context

    • Putting stuff you have learned into a markdown file is a very "shallow" version of continual learning. It can remember facts, yes, but I doubt a model can master new out-of-distribution tasks this way. If anything, I think that Google's Titans[1] and Hope[2] architectures are…

      andy12_View on HNParent context

  1. The Q, K, V Matrices 1 comment
    • Per your point 4, some current hyped work is pushing hard in this direction [1, 2, 3]. The basic idea is to think of attention as a way of implementing an associative memory. Variants like SDPA or gated linear attention can then be derived as methods for optimizing this memory…

      psb217View on HNParent context

  2. The dawn of a world simulator 1 comment
    • Have you looked at Titan and MIRAS where they use online/updating associative memory that happens to be read out via next-token prediction? https://research.google/blog/titans-miras-helping-ai-have-lo... https://arxiv.org/abs/2501.00663 https://arxiv.org/pdf/2504.13173 Much…

      mycallView on HNParent context

    • Titans: Learning to Memorize at Test Time https://arxiv.org/abs/2501.00663

      AlifatiskView on HNParent context

    • From the blog: https://arxiv.org/abs/2501.00663 https://arxiv.org/pdf/2504.13173 Is there any other company that's openly publishing their research on AI at this level? Google should get a lot of credit for this.

      okdood64View on HNParent context

  3. NeurIPS 2025 Best Paper Awards 1 comment
    • Paper https://arxiv.org/abs/2501.00663

      brrrrrmView on HNParent context

    • The paper the article is based on [1] treats “Titans” as a plural: “Titans are capable of solving problems beyond TC^0, meaning that Titans are theoretically more expressive than Transformers….” [1] https://arxiv.org/pdf/2501.00663

      tkgallyView on HNParent context

    • Something like this, using Simon Willison's llm cli, will give you a better experience than such generated articles unless your goal is explicitly to read blogs. wget https://arxiv.org/pdf/2501.00663 -O - | pdftotext - - | llm -s "Explain the following paper assuming I am…

      imjonseView on HNParent context

    • Titans has a new approach to longer and faster memory compared to transformers. https://arxiv.org/html/2501.00663v1

      SiddanthEmaniView on HNParent context

    • There is a LOT of effort in the research community currently: 1. Improving the Self-Attention in the Transformer as is, keeping the quadratic complexity, which has some theoretical advantage in principle[1]: The most hyped one probably DeepSeek's Multi-Latent Attention[15]…

      korbipView on HNParent context

    • The AI hardware race is still going strong, but with so many rapid changes to the fundamental architectures, it doesn't make sense to bet everything on specialized hardware just yet.. It's happening, but it's expensive and slow. There's just not enough capacity to build memory…

      mkromanView on HNParent context

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