{"slug": "head-to-head-grok-4-3-vs-phi-4-reasoning", "title": "Head to head: grok-4.3 vs Phi-4-reasoning", "summary": "Grok-4.3 defeated Phi-4-reasoning 38.0 to 4.0 in a head-to-head test across four text tasks, primarily due to superior instruction-following and output discipline. Phi-4-reasoning repeatedly failed by providing explanatory prose instead of requested code, JSON, or polished messages, making it unsuitable for real workflows.", "body_md": "grok-4.3 wins this matchup in a rout, 38.0 to 4.0, and the reason is almost embarrassingly simple: it completed the assignments. Across all four tasks, A delivered the requested artifact in the requested format; B repeatedly drifted into explanation, reasoning, and prose where the prompt explicitly asked for code, JSON, or a polished message.\n\nThe clearest failure came in **python-log-redactor**. grok-4.3 returned code only, as instructed, and did so with a concise regex-based implementation that preserved surrounding punctuation. Phi-4-reasoning didn’t really attempt the deliverable; it produced explanatory text instead of the function, which is a hard fail on a task where format compliance is the job.\n\nThe same pattern held in **status-update-delay** and **meeting-notes-summary**. A wrote an executive-ready delay update with the right tone, all required facts, and a single clean ask. It also produced a proper two-sentence summary plus valid JSON with the specified keys for the notes task. B, by contrast, kept lapsing into chain-of-thought-style meta output and disclaimers—exactly the kind of behavior that makes a model unusable in real workflows even when some underlying facts are present.\n\nIn **messy-orders-to-json**, grok-4.3 again did the unglamorous work correctly: valid JSON only, correct schema, normalized values, sorted by `order_id`\n\nascending. Phi-4-reasoning again missed the core requirement by wrapping the answer in analysis text. That is not a near miss; it is the difference between something a system can consume and something a human has to repair.\n\n**Final call: grok-4.3, easily.** This wasn’t a nuanced stylistic win; it was a decisive demonstration that instruction-following and output discipline matter more than performative reasoning. Phi-4-reasoning lost because it kept talking about the task instead of doing it.\n\n### How they were tested\n\nWe ran 4 fresh text tasks, generated on the fly for this matchup so neither model could prepare in advance, and had gpt-5.4 score each one. grok-4.3 scored 38.0 to Phi-4-reasoning's 4.0.\n\n#### 1. python-log-redactor\n\nPractical coding — Python. Return code only. Write a function `redact_log(line: str) -> str`\n\nthat prepares app log lines for sharing with vendors. Replace any IPv4 address with `[IP]`\n\nand any email address with `[EMAIL]`\n\n, but leave everything else unchanged. Treat IPv4 as four 1–3 digit parts separated by dots; you do not need to validate 0–255 ranges. Preserve punctuation around matches. Examples: - `db timeout from 10.14.9.3 for maya@northpass.io`\n\n-> `db timeout from [IP] for [EMAIL]`\n\n- `alert: user=sam+ops@acme.tools, src=172.16.0.12:443`\n\n-> `alert: user=[EMAIL], src=[IP]:443`\n\nImplement just the function, no tests or explanation.\n\n**Winner: grok-4.3** — A follows the instruction to return code only and provides a concise, correct regex-based implementation that preserves surrounding punctuation. B does not provide the requested function implementation at all and instead outputs explanatory prose, violating the format and task requirements.\n\n#### 2. status-update-delay\n\nProfessional writing — Draft a workplace status update for the VP of Operations. Audience: busy executive. Tone: calm, accountable, no blame. Length: 120–150 words. Situation: the warehouse scanner rollout at Ridgeway Fulfillment is slipping by 9 days because 37 of 220 devices arrived with bad batteries and the replacement shipment from Soltera is due Tuesday. Include: what happened, customer impact (none to current orders), mitigation (reassigning 14 spare units from the Phoenix site, extending evening staging shifts through Friday), and the new target go-live date of May 21. End with one clear ask: approval for up to $6,800 in expedited freight if the replacement shipment misses Tuesday.\n\n**Winner: grok-4.3** — A cleanly follows the prompt with the right executive tone, includes all required facts, ends with a single clear ask, and stays concise. B is largely meta-reasoning instead of the requested status update, violates the format and audience needs, and does not deliver an appropriate executive-ready draft.\n\n#### 3. meeting-notes-summary\n\nSummarization & extraction — Read the meeting notes below, then provide: 1) a 2-sentence summary 2) a JSON object with keys `decision`\n\n, `owner`\n\n, `deadline`\n\n, `risks`\n\n(array) Meeting notes: - AtlasCare mobile app triage, Tues 09:00 - Crash reports spiked after v3.18.2, mostly on Android 12 when opening lab results from push notifications. - Priya reproduced it on a Pixel 5; stack trace points to a null patientId in the deep-link handler. - Mateo can patch today, but QA says full regression before Thursday is unrealistic. - Lena: legal already approved a limited rollback if we keep appointment booking intact. - Agreed plan: ship a server-side flag by 3pm to disable lab-result push opens on Android only; hotfix app build by Thursday 6pm; rollback only if crash-free rate is still under 99.2% by Friday noon. - Priya owns the flag change. Mateo owns the hotfix build. Jordan to post a support macro for affected users. - Risk: analytics dashboard is delayed ~4 hours, so Friday assessment may rely on Play Console plus Zendesk tickets.\n\n**Winner: grok-4.3** — Model A directly follows the requested format with a clear 2-sentence summary and a valid JSON object using the specified keys. Model B is mostly chain-of-thought/meta commentary, adds unnecessary disclaimers, and does not cleanly adhere to the prompt despite containing some relevant extracted details.\n\n#### 4. messy-orders-to-json\n\nData wrangling / structured output — Convert the messy order notes below into valid JSON only. Output an object with one key, `orders`\n\n, whose value is an array of objects sorted by `order_id`\n\nascending. Each object must have exactly these keys: `order_id`\n\n(string), `customer`\n\n(string), `sku`\n\n(string), `qty`\n\n(integer), `rush`\n\n(boolean), `ship_by`\n\n(string in YYYY-MM-DD), `notes`\n\n(string). Rules: trim spaces, normalize SKU to uppercase, interpret `rush: yes/y/true`\n\nas true and `no/n/false`\n\nas false, and use an empty string for missing notes. Messy data: #A-104 | cust=Blue Harbor Cafe | sku: tm-44 | qty 6 | rush yes | ship_by 2026/02/07 | notes: leave at rear door A-102; customer = Nori & Pine ; SKU = qz-9 ; quantity=12 ; rush = n ; ship-by=2026-02-05 ; order A-111 / customer: Helio Labs / sku kk-210 / qty: 3 / rush: TRUE / ship_by: 2026-02-09 / notes: Attn Mira ID=A-107, cust=Juniper School, sku=bx-7, qty=25, rush=no, ship_by=2026-02-08, notes=PO 8831\n\n**Winner: grok-4.3** — Model A follows the instruction to output valid JSON only, uses the correct schema, normalizes values properly, and sorts by order_id ascending. Model B does not provide the requested JSON output and instead includes extraneous analysis text, so it fails the core formatting requirement.\n\nSee every prompt and the full side-by-side outputs in the [interactive Head-to-Head](/head-to-head/head-to-head-grok-4-3-vs-phi-4-reasoning).", "url": "https://wpnews.pro/news/head-to-head-grok-4-3-vs-phi-4-reasoning", "canonical_source": "https://runtimewire.com/article/head-to-head-grok-4-3-vs-phi-4-reasoning", "published_at": "2026-06-20 14:07:52+00:00", "updated_at": "2026-06-20 14:11:16.668474+00:00", "lang": "en", "topics": ["large-language-models", "ai-products", "ai-tools"], "entities": ["grok-4.3", "Phi-4-reasoning", "gpt-5.4", "Soltera", "Ridgeway Fulfillment", "Phoenix"], "alternates": {"html": "https://wpnews.pro/news/head-to-head-grok-4-3-vs-phi-4-reasoning", "markdown": "https://wpnews.pro/news/head-to-head-grok-4-3-vs-phi-4-reasoning.md", "text": "https://wpnews.pro/news/head-to-head-grok-4-3-vs-phi-4-reasoning.txt", "jsonld": "https://wpnews.pro/news/head-to-head-grok-4-3-vs-phi-4-reasoning.jsonld"}}