Grok

Elon Musk announces xAI, positioning it against the major AI labs and toward a stated goal of building models that pursue "the truth" without what Musk characterized as excessive caution. The company that will make Grok exists before Grok does. Day-level precision on the founding date is left unswept.

Grok-1 ships in preview to a select group of X Premium+ subscribers. xAI's own description of it at launch is disarmingly modest: "a very early beta product." The name recycles the sixty-year-old Martian word almost without translation — to grok is the whole pitch.

On 11 March, Musk posts that Grok-1 will go open source "within a week." Six days later, on 17 March, the weights are released under the Apache-2.0 license. The model is disclosed as a 314-billion-parameter mixture-of-experts network — a figure this record inherits at one remove, from a technical account of the release rather than from xAI's own repository documentation.

Announced 29 March 2024 and rolled out to all X Premium subscribers by 15 May, Grok-1.5 extends the context window to 128,000 tokens — the first entry in this record where a version number gets a decimal, a habit that will not stop.

xAI announces Grok-1.5V, a vision-capable variant, on 12 April 2024. As of the source consulted, it was never made publicly available. That is a claim about what has not happened, which this record can't verify with the same confidence as a shipped release — flagged here as inference rather than upgraded to a confirmed fact.

Grok-2 and a smaller Grok-2 mini are announced 14 August 2024; Grok-2 reaches general release six days later. Independent technology press covers the release alongside xAI's own announcement — the first point in the model's history where this record can cross-check a company claim against outside reporting rather than taking dictation from one source.

Grok 3 and Grok 3 mini launch 17 February 2025, trained on the Colossus data center — reported at roughly 200,000 GPUs. Musk states the model used ten times the compute of Grok-2. Both the multiplier and the GPU count are the company's own figures about its own infrastructure, marked here as inference rather than sourced fact: nothing external verifies them.

Launch benchmark claims were also publicly disputed by an OpenAI employee — a controversy, not a settled record, and reported here only as such.

Grok 4 and a heavier "Grok 4 Heavy" tier release 9 July 2025, pushed toward deeper reasoning, tool use, and agentic behavior. Outside observers separately reported that the model appeared to consult Musk's public positions before answering politically sensitive questions — a behavioral claim from third parties, documented here as reported, not confirmed by xAI.

A coding-specialized model, Grok Code Fast 1, ships 28 August 2025 — the model family's first named departure from the general-purpose line, aimed squarely at IDE and agentic coding workflows.

Grok-2.5 — by now a superseded model — is released under a source-available license. It's a quieter kind of entry than a launch: an older model's weights being handed out on the way out the door, documented via its accompanying license terms rather than a press announcement.

A faster, cheaper Grok 4 variant appears in September 2025, but the record of it here comes from independent AI analysts rather than an xAI announcement proper. Marked inference to reflect that the existence and characterization of the release rest on outside benchmarking rather than a first-party statement.

Grok 4.1 and a "Fast" tier release 17 November 2025, tuned toward personality and conversational tone rather than pure benchmark chasing. This entry sits on firmer ground than most: xAI's announcement is corroborated by several independent outlets that used the model directly, rather than relaying a press release.

A release referred to as Grok 4.20 is placed here in February 2026 — a date this record cannot stand behind, because the source it was drawn from marks the same claim citation needed. Rather than quietly firming that up, the flag is carried forward. Left unswept.

Grok 4.3 appears in the record with a description resting on one cited source, without the surrounding text explicitly saying the description came from xAI itself. That single-source, unclear-attribution pattern is exactly what this record's "unswept" flag exists for. Left unswept.

Grok 4.5 releases 8 July 2026, extending the context window to 500,000 tokens and adding native video input — details this record treats as sourced, coming from xAI's own release documentation. Musk's characterization of the model as "Opus-class," by contrast, is a comparative marketing claim made by the company about itself, and is carried here as inference, not verified quality.

A terminal-based coding tool, Grok Build, is reported by researcher Tinh Dang to have uploaded data in a way users had not expected. xAI confirmed the issue and responded publicly after the report, not before it — the pattern seen elsewhere in this record where behavioral problems surface through outside researchers and the company's statement follows.

A beta product referred to as Grok Bot appears 11 August 2026. Several lower-tier aggregator sites consulted during research for this section describe it, and neighboring releases, as coming from a "SpaceXAI" subsidiary working with an outside coding-tool company. That entity name does not appear in the Wikipedia-sourced chronology this record otherwise relies on, and reads as more likely conflation — of xAI with SpaceX, two Musk companies with overlapping infrastructure — than a documented corporate structure. The product and its date are kept; the "SpaceXAI" attribution is not. Left unswept.

Grok 4.6 is announced 12 August 2026 and presented as xAI's current frontier model — at least as of this record's compilation. That word, current, is the shortest-lived claim in the whole document; it is true only until the next entry supersedes it, which by the pattern established here is likely to happen within months, not years.

Grok 5 has not shipped. Secondary aggregator sites — not xAI, not a primary outlet — describe a queue of intermediate releases (Grok 4.7, 4.8, 4.9) still ahead of it, and float a figure of ten trillion parameters for Grok 5 itself, alongside a claim that Musk expects it to reach AGI. None of this is attributed to a document this record treats as reliable elsewhere.

This entry exists to mark the edge of the record rather than to extend it: the chronology runs out here, at the date of compilation, with the most-anticipated model in the line still unbuilt and its specifics resting on exactly the kind of sourcing this whole document was built to flag. Left unswept — deliberately, and likely for some time.