Limitless AI
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Limitless AI is an American personal artificial intelligence company best known for the Limitless Pendant, a small clip-on wearable that captures ambient conversational audio and pipes transcripts, action items, and meeting summaries into a companion application across web, macOS, Windows, iOS, and Android. The company was founded in 2020 as Rewind AI by Dan Siroker (formerly co-founder and chief executive officer of Optimizely) and Brett Bejcek, and operated for its first phase as a local-only Mac application that recorded screen, microphone, and system audio, used optical character recognition to make the resulting data searchable, and stored everything on the user's machine.[^1][^2] In April 2024 the company rebranded to Limitless AI and announced a hardware-first pivot built around the Pendant, a USB-C charged wearable retailing at US$99 with a quoted 100-hour battery life.[^3] By December 2025 Limitless had raised more than US$33 million in venture capital from investors including [[andreessen_horowitz|Andreessen Horowitz]], New Enterprise Associates (NEA), First Round Capital, and OpenAI chief executive [[sam_altman|Sam Altman]], before being acquired by [[meta|Meta]] for an undisclosed amount and folded into the company's Reality Labs wearables organization.[^4][^5]
| Limitless AI | |
|---|---|
| Former name | Rewind AI (2020 to 2024) |
| Founded | 2020 (incorporated as Rewind AI, Inc.) |
| Founders | Dan Siroker, Brett Bejcek |
| Headquarters | San Francisco, California, United States |
| Key products | Limitless Pendant (hardware), Limitless app (macOS, Windows, iOS, Android, web); Rewind for Mac (legacy) |
| Pendant price | US$99 (launch); US$199 (later retail) |
| Pendant battery life | Approximately 100 hours (quoted) |
| Total funding | More than US$33 million (pre-acquisition) |
| Notable investors | Andreessen Horowitz, New Enterprise Associates, First Round Capital, Sam Altman |
| Pendant announced | 15 April 2024 |
| Acquisition | Acquired by Meta, announced 5 December 2025 |
Rewind AI, Inc. was incorporated in 2020 by Dan Siroker and Brett Bejcek, with Siroker as chief executive officer. Siroker had previously co-founded the experimentation platform Optimizely in 2009 and served as its chief executive until 2017, after a career that included product management roles at Google (where he worked on Google Chrome) and analytics leadership for Barack Obama's 2008 presidential campaign.[^6] In his public remarks Siroker has tied the company's founding to a personal experience: he lost a significant portion of his hearing in his twenties, and after he began wearing hearing aids in his early thirties he described the technology as "gaining a superpower," prompting him to ask whether software could augment human memory the way the hearing aid had augmented his hearing.[^7]
Rewind's first product was a macOS application released to a closed waitlist in late 2022. The app continuously recorded everything that appeared on the user's screen, along with microphone and system audio, then used on-device optical character recognition and [[speech_recognition|speech recognition]] to make every word and pixel searchable.[^1] All data remained on the local machine; recordings were not uploaded to the cloud, and users could exclude specific applications from capture. The launch attracted considerable attention because the recordings were aggressively compressed: company materials claimed that more than ten gigabytes of raw screen and audio capture could be compressed into a file of a few megabytes "without major loss of quality," and the app was restricted to [[apple_silicon|Apple Silicon]] Macs because it leaned on hardware features of those system-on-chips to keep CPU usage low.[^1]
The product became a frequent topic on Twitter (now X), where Siroker also used the platform unconventionally to solicit funding. In a public link circulated in 2023, he asked investors to submit blind term-sheet bids; the campaign accumulated more than a million impressions, and the company reported over 170 committed offers from the resulting inbound interest.[^8] Rewind closed a US$10 million seed round in late 2022 led by Andreessen Horowitz with participation from First Round Capital and Vela Partners, then a Series A of approximately US$15 million in mid-2023 at a US$350 million valuation, led by New Enterprise Associates.[^4][^9]
Despite the press attention, the Rewind Mac app remained a niche tool. Internal and external commentary highlighted three limitations: it ran only on a single device, it captured nothing the user did away from that machine, and the always-on local recorder triggered privacy concerns from users sharing a Mac with others or working in regulated environments. By 2023 Siroker had begun publicly floating the idea of moving from "local and desktop context" to "cloud and audio context," with a wearable as the bridge.[^7]
Siroker first publicly described the wearable concept on X in October 2023, posting a short video of a small clip-on prototype and inviting people to put down a US$59 deposit on a future production unit. Coverage at the time treated the device as a side project for Rewind, with the Mac app remaining the headline product.[^3] The company formally announced both the Limitless brand and the production Pendant on 15 April 2024. The launch announcement, covered first by The Verge's David Pierce, framed the company as a hardware-first personal AI vendor and positioned the existing Mac app as a legacy line item that would continue to operate but would receive no new features.[^10][^3]
The Pendant launch generated unusually strong inbound demand: more than 10,000 pre-orders were taken within the first 24 hours, of which approximately 40 percent originated outside the United States, according to Siroker. Initial pre-orders were honored at the original US$59 price; subsequent sales used a US$99 launch price, later raised to US$199 once volume shipping began.[^3][^7] Production targeted an August 2024 first-batch ship date, but actual delivery slipped into the second half of 2024 and into early 2025 for many buyers, mirroring delays experienced by other early AI hardware startups.[^11]
The original Rewind app continued to receive updates throughout 2024 and into 2025 but was eventually wound down. After the December 2025 Meta acquisition, Limitless announced that the Rewind Mac app would be shut down and that customer data could be exported or deleted, while Pendant data would migrate to the renamed Limitless application.[^5]
On 5 December 2025 Limitless announced that it had agreed to be acquired by [[meta|Meta]], with the engineering and product team joining Meta's Reality Labs wearables organization. The financial terms were not disclosed publicly, though reporting placed the value at the high end of acqui-hire range; Reuters and TechCrunch both noted that Limitless had raised more than US$33 million in venture capital prior to the deal.[^5][^12] As part of the acquisition, the company announced that Pendant hardware sales were halted; existing customers received a free year of the paid "Unlimited" tier; and the legacy Rewind for Mac product would be discontinued, with users given a window to export or delete their stored data.[^5]
The deal followed a broader pattern in 2025 of large incumbents absorbing standalone AI-wearable startups. Amazon acquired the Bee wristband recorder in July 2025; HP had earlier acquired the assets of Humane, the maker of the [[humane_ai_pin|Humane AI Pin]], in early 2025 before shutting that device down; and Meta itself had been investing heavily in [[meta_ray_ban_ai|Ray-Ban AI smart glasses]] developed in partnership with EssilorLuxottica.[^13][^14]
The Limitless Pendant is the company's signature product. It is a small, roughly coin-sized aluminum disc, about 1.25 inches (32 mm) in diameter and 0.62 inches (16 mm) thick, with a magnetic backing that allows it to clip to clothing or be worn on a lanyard. The device carries multiple microphones, Bluetooth Low Energy, Wi-Fi, and an internal battery quoted at roughly 100 hours of standby and active recording time. It charges over USB-C. The Pendant has no display, no buttons in the conventional sense (a single tap surface is used for bookmarking moments and toggling consent mode), and importantly no camera; the latter omission was emphasized by the company as a deliberate privacy choice.[^15][^3][^10]
Pendants shipped in several anodized aluminum colorways including black, forest green, and a pink finish. The device is rated IP54 for dust and water resistance, sufficient to survive splashes and sweat but not full submersion.[^15][^16] In its initial form factor the Pendant relied on a paired smartphone or computer for connectivity; later firmware updates added local audio buffering so the device could keep recording when out of range and sync once a connection was restored.[^15]
Audio captured by the Pendant is streamed (or batch-uploaded if offline) to Limitless's cloud, where it is run through [[automatic_speech_recognition_models|automatic speech recognition]] models and then through one or more [[large_language_model|large language model]] backends to produce structured outputs. The product's terminology refers to each capture session as a "lifelog," and the application surfaces several derived artifacts per lifelog: a diarized transcript with speaker labels, a short summary, a list of extracted action items and follow-ups, and a daily roll-up of the user's conversational activity.[^17][^18] The company's mobile application supports transcription in more than 100 languages.[^15]
In 2025 Limitless released a developer API ("Limitless API," in beta at time of launch) that allowed external software to query a user's lifelogs, search transcripts, paginate through history, and download raw OGG/Opus audio for a given time window. The API supported only Pendant data, not the older Mac and Windows desktop meeting recorder, and required user authorization tokens. The API was used in third-party Model Context Protocol (MCP) servers that exposed Pendant memory to chat assistants such as [[claude_ai|Claude]].[^18]
The Pendant ships with two privacy-oriented features that the company has emphasized in marketing and documentation. The first is Consent Mode, an opt-in setting whereby the device identifies newly heard voices and refuses to retain or transcribe those voices' speech until the speaker has been heard to verbally agree to be recorded; the wearer is responsible for prompting the consent question. The mode is intended primarily to address jurisdictions that require all-party consent for recording private conversations.[^10][^15]
The second is the company's so-called Confidential Cloud, an encrypted processing tier built on hardware-isolated trusted execution environments. Limitless has described the design as using AMD's Secure Encrypted Virtualization with Secure Nested Paging (SEV-SNP) to run inference and storage workloads inside attested confidential virtual machines, such that "your employer, us as a software provider, and the government cannot decrypt your data without your permission, even if given a subpoena."[^3] AMD SEV-SNP is a memory-encryption and integrity-protection extension that creates isolated guest memory pages whose contents and integrity cannot be observed or modified by the host hypervisor, even one that has been compromised; combined with remote attestation, the technology is widely used in commercial "confidential computing" offerings on cloud platforms.[^19] In Limitless's framing, the Pendant's audio and derived transcripts never appear in plaintext outside of the attested enclave, and the encryption keys are bound to the user's own credentials.
The architecture has not been independently audited in published form, and the company has not released a full technical paper describing key custody or the precise inference stack used inside the enclave. Reviewers and security commentators have noted both that hardware-backed enclaves substantially raise the bar against passive cloud-side data exposure, and that the security guarantees depend on the soundness of the underlying TEE implementation, the attestation chain, and the company's own key-management procedures.[^19][^20]
At hardware launch in April 2024 the Pendant was offered at US$99 for new buyers, with US$59 honored for early X-platform deposits. Retail prices later rose to US$199 as production stabilized.[^3][^16] On the software side, Limitless operated a freemium model: a free tier provided unlimited audio capture with a monthly cap of AI-processed minutes (initially 10 hours per month, later 20 hours per month), while a paid "Pro" or "Unlimited" tier at US$19 to US$29 per month unlocked unlimited transcription, advanced AI features, app integrations, and the developer API. After the Meta acquisition the company committed to a free year of the paid tier for existing customers.[^3][^15][^5]
Although superseded as the company's main product, the original Rewind for Mac application remained available through 2024 and 2025 and is part of the documentary record of the company. The application targeted Macs equipped with [[apple_silicon|Apple Silicon]] chips and continuously captured the screen, microphone, and system audio. Captured frames were processed with on-device [[ocr_models|optical character recognition]] to extract text and with [[speech_recognition|speech recognition]] to transcribe spoken audio; the resulting index made everything the user had seen, said, or heard on the Mac searchable through a single search bar.[^1]
The product's signature engineering claim was extreme compression of the captured stream. Marketing materials and contemporary reviews cited a ratio of roughly 3,750 to 1, transforming a multi-gigabyte raw capture into a file in the low single-digit megabyte range. This figure was achieved by storing keyframes plus structured text extracted via OCR rather than full-fidelity video.[^1] Storage and compute remained local; nothing was synced to a server.
Later versions added a meeting-notes feature (a notetaker bot named "Rewind Pendant" before the hardware was renamed and unbundled), an "Ask Rewind" natural-language query interface backed by GPT-4 and Claude models, and integrations with calendars and chat applications. The Rewind app was, in effect, the company's research vehicle for what eventually became the Limitless lifelog: a unified, searchable, cross-source memory built on top of large language models.[^21]
In December 2025, following the Meta acquisition, Limitless announced that Rewind for Mac would be discontinued. The application stopped receiving updates, and users were directed to export or delete their data before the shutdown window closed.[^5]
At a high level, the Pendant captures audio via beam-forming microphones and uses voice-activity detection to distinguish speech from background noise. Audio is encoded locally (the public API uses OGG/Opus) and uploaded over Bluetooth-tethered or Wi-Fi connectivity to the Limitless backend.[^18]
Server-side processing follows a multi-stage pipeline:
Throughout this pipeline, the company's stated design intent is for plaintext audio and transcripts to remain inside an attested confidential virtual machine. The user's own client decrypts results before display.[^3]
Pre-acquisition, Limitless raised funding in three principal tranches, totaling more than US$33 million.[^4][^5]
| Round | Approximate date | Approximate amount | Notable participants |
|---|---|---|---|
| Seed | Late 2022 | US$10 million | Andreessen Horowitz (lead), First Round Capital, Vela Partners |
| Series A | Mid-2023 | About US$15 million | New Enterprise Associates (lead), Andreessen Horowitz, First Round Capital |
| Later strategic | 2024 to 2025 | Remainder of total | Sam Altman and additional strategic investors |
In addition to the institutional lead investors, public reporting and the company's "About" page have identified personal cheques from [[sam_altman|Sam Altman]] and from Clement Delangue, co-founder and chief executive of [[hugging_face|Hugging Face]], among individual backers.[^4][^22] The Series A valued the company at roughly US$350 million.[^9]
Founder Dan Siroker stated at the time of the April 2024 Pendant launch that the company did not plan to raise further institutional capital before shipping the hardware, betting that pre-order revenue plus existing cash reserves would carry the company through manufacturing.[^3]
Initial press response to the Pendant in April 2024 was substantially more positive than reception of two competing devices that had launched in the prior months, the [[humane_ai_pin|Humane AI Pin]] and the [[rabbit_r1|Rabbit R1]]. The Verge's David Pierce wrote that the Pendant "actually looks useful" and praised its narrow focus on transcription and meeting memory rather than attempting to replace the smartphone outright.[^10] Tom's Guide and several other consumer-technology outlets ran similar coverage, contrasting the Pendant's US$99 price and meeting-focused use case with the US$699 Humane AI Pin and US$199 Rabbit R1.[^11]
By 2025, with units in users' hands for several months, longer-form reviews appeared. The Wall Street Journal's Joanna Stern compared the Pendant against the Amazon-acquired Bee Pioneer wristband and the Plaud NotePin in a multi-device review titled "I Recorded Everything I Said for Three Months," published in May 2025. Stern reported that the wearables were "useful but also creepy" and indicated a personal preference for the wrist-worn Bee over the Pendant in everyday use, while granting that each device occupied a distinct niche.[^23] Independent reviewers writing on Substack, YouTube, and product-review sites generally praised the Pendant's daily-summary feature and the Confidential Cloud architecture but flagged battery anxiety in real-world all-day use (with reported all-day usage closer to 6 to 7 hours when actively streaming than the 100-hour standby figure), occasional inaccuracies in speaker diarization, and frustration with the iOS application's organizational features.[^16]
In April 2024 Marques Brownlee (MKBHD) published "The Worst Product I've Ever Reviewed... For Now," a widely shared critical review of the Humane AI Pin that observers credit with reframing the AI-wearable conversation for the general public. Limitless executives have referenced the Brownlee review in interviews as motivating their decision to constrain the Pendant's promised feature set to capabilities that worked at launch.[^24][^7]
The Pendant attracted privacy commentary from its first announcement. The core concern was that an always-listening wearable defaults to capturing the speech of every person near the wearer, not just the wearer themselves. United States recording law is split: federal law and most states permit one-party consent to the recording of an in-person conversation, but a substantial minority of states (including California, Florida, Illinois, Maryland, Massachusetts, Pennsylvania, and Washington) require all-party consent. California's Penal Code Section 632 (the Invasion of Privacy Act, CIPA) is among the strictest, with criminal penalties of up to US$2,500 and one year of jail for a first offense and civil damages of US$5,000 per violation.[^25][^26]
Limitless's Consent Mode was designed in part as a response to this legal landscape, asking new speakers to verbally consent to be recorded before their speech is retained. Critics, including legal commentators at Goodwin Procter and at trade-press recording-law sites, noted in 2024 and 2025 that the architecture still relies on the wearer to elicit consent at the right moment, and that ambient capture in public spaces or workplaces in all-party jurisdictions remains legally fraught regardless of device design.[^25][^27] The company's product literature acknowledged this and recommended that buyers operating in all-party jurisdictions or in regulated workplaces use the Pendant only where consent has been obtained.
Independent commentators raised parallel concerns about social etiquette. A small but visible body of writing in 2024 and 2025 questioned the social acceptability of being recorded by a stranger's pendant in casual settings, even when recording was technically legal. Reviewers contrasted this with the somewhat less ambiguous social signal of a smartphone-on-the-table recording during a meeting.[^23]
Beginning in 2024 a small cluster of always-on listening wearables came to market or were announced, of which Limitless was an early and prominent participant. Each emphasized a different combination of form factor, audience, and feature set.
| Product | Company | Form factor | Focus | Approximate price |
|---|---|---|---|---|
| Limitless Pendant | Limitless AI | Clip-on disc, pendant | Meeting notes, lifelog, action items | US$99 to US$199 |
| [[humane_ai_pin | Humane AI Pin]] | Humane | Magnetic chest pin with laser projector and camera | Smartphone replacement |
| [[rabbit_r1 | Rabbit R1]] | Rabbit Inc. | Handheld with screen, scroll wheel, camera | App-agent device |
| Friend | Friend, Inc. (Avi Schiffmann) | Necklace puck | Companionship and emotional support | US$99 |
| Plaud NotePin | Plaud AI | Clip-on note recorder | Meeting recording and notes | About US$159 |
| Bee Pioneer | Bee Computer (acquired by Amazon) | Wristband | Daily lifelog, productivity | About US$50 |
The Humane AI Pin was met with broadly negative reviews after launch, suffered overheating and battery issues, and was effectively wound down in 2025 after parent company Humane was acquired by HP for approximately US$116 million in an asset deal. Humane subsequently terminated server connectivity, rendering existing pins largely inoperable.[^28] The Rabbit R1 was criticized after launch for offering little that a smartphone could not already do, although Rabbit Inc. continued to ship firmware updates through 2025.[^29] Friend, founded by then-22-year-old Avi Schiffmann and funded in part by figures from the Solana and Perplexity ecosystems, took a deliberately different positioning, marketing itself as a companion device rather than a productivity tool. The two products' visual similarity (both small, round pendants worn near the chest) generated extensive press commentary about naming and brand confusion in 2024.[^30][^31] Amazon's acquisition of Bee in July 2025 reinforced the perception that listening wearables would be absorbed into platform incumbents, a pattern that culminated in Meta's December 2025 acquisition of Limitless itself.[^13][^5]
Limitless AI sits at the intersection of several distinct technical and commercial trends in the period from 2022 to 2025. As an engineering effort, it is a real-world test of three propositions: that consumer-grade [[automatic_speech_recognition_models|automatic speech recognition]] is now accurate enough across languages to make ambient transcription a practical product; that downstream [[large_language_model|large language model]] processing can convert that transcription into structured artifacts (notes, action items, summaries) of sufficient quality to displace handwritten notes for at least some users; and that hardware-isolated trusted execution environments such as AMD SEV-SNP can serve as the privacy substrate for sensitive cloud workloads marketed to mainstream consumers.[^19][^15]
As a commercial story, the company illustrates the difficulty of monetizing personal-data tooling without distribution leverage. The original Rewind product had passionate users but limited reach, in part because it ran only on macOS and in part because it required users to install a permanent local recorder. The Pendant offered a hardware "social contract" (a visible recording indicator, a clip-on form factor that signaled intentionality) and a cloud architecture that worked across devices. Its eventual acquisition by Meta, the largest social platform company, is itself a data point on how independent personal-AI hardware fared in the 2024 to 2025 wave: most original hardware-first AI wearables of this period (Humane, Rabbit, Friend, Bee, Limitless) ended up either acquired, repositioned, or wound down within roughly two years of announcement, with the Meta and Amazon acquisitions of Limitless and Bee respectively offering at least graceful exits for investors and employees.[^5][^13]
The pivot from Rewind to Limitless also exemplifies how the broader "personal AI" category shifted from a desktop-software paradigm (a smarter Spotlight on a Mac) to an embodied paradigm (a wearable that follows the user out of the office) over roughly eighteen months in 2023 to 2024, paralleling moves by larger companies into [[meta_ray_ban_ai|smart glasses]] and other ambient devices.[^14]
Several criticisms recur across press coverage, reviewer reports, and academic commentary:
Dan Siroker is the company's co-founder and was its chief executive officer through the Meta acquisition. He holds a bachelor's degree in computer science from Stanford University and worked as a product manager at Google, where he was on the Google Chrome team and worked on an AdWords feature reported to have grown to several hundred million dollars in annual run-rate revenue. He served as director of analytics for Barack Obama's 2008 presidential campaign before co-founding Optimizely in 2009, where he was chief executive officer until 2017 (Optimizely later grew to more than US$120 million in annual recurring revenue under his tenure). Siroker has spoken publicly about losing significant hearing and receiving hearing-aid implants in his early thirties, an experience he has linked to his interest in technology that augments biological human capabilities.[^6][^7]
Brett Bejcek is the company's co-founder. He was previously a product and engineering lead at music streaming and analytics companies before joining Siroker to start Rewind AI in 2020.[^32]
The company's public "About" page in 2025 listed several additional senior team members in engineering, product, and design roles, including a chief technology officer with prior infrastructure experience and a head of design responsible for the Pendant's industrial design.[^33] The Pendant's industrial design was widely credited in press coverage to the design studio Ammunition, which had previously designed Beats headphones, though Limitless did not make formal public statements about external design partnerships.[^21]
The Pendant occupies a specific design point in a broader landscape of AI-enabled wearables. Other devices in or near the category include:
Beyond hardware, the Pendant's software architecture (capture, transcribe, summarize, action-extract) shares its surface area with software-only meeting assistants such as Otter.ai, Granola, Fireflies, and Microsoft's Recall feature for Copilot+ PCs, all of which competed for the same market of users who wanted automatic notes from meetings.