ERNIE (文心) is Baidu’s model family, and for search it matters more than any single algorithm update now does. The same models write the AI answers at the top of Baidu Search, power the Wenxin assistant that replaced the ERNIE Bot website (文心一言), and are sold to developers through Baidu’s Qianfan cloud. This page lists ERNIE model releases, ERNIE Bot milestones and the Baidu Search changes built on them, newest first. Dates come from Baidu announcements, the ERNIE blog, Xinhua, or Reuters reporting. Early research releases where only the month is reliable are marked that way. Classic ranking changes are on the Baidu algorithm updates page.
| Date | Update | What changed | Why it matters |
|---|---|---|---|
| 30 October 2026 | Baidu Search AI API price cut | Promotional price of ¥4.9 per 1,000 calls for the Enhanced tier and ¥9.9 for Flagship, from 30 October to 31 December. Enhanced is capped at one million calls, then billed at the ¥40 list price. | Undercuts DeepSeek’s ¥5 search API, so more Chinese agents will ground their answers in Baidu’s index. |
| 27 October 2026 | Wenxin Unlimited OCR 2 | Document OCR model open-sourced. | Better reading of scanned and long documents widens what Baidu’s models can index and cite. |
| 16 September 2026 | AI Traffic Analysis in Baidu Webmaster tools | The Search Resource Platform began reporting how often a site is cited in AI answers, with impressions and clicks. | The first official Baidu data on AI citations, though early reports show very few clicks. |
| 25 June 2026 | ERNIE Bot website closed for new questions | The 文心一言 site stopped taking questions; service moved to the Baidu Wenxin (文心) site on 26 July, with data export until 25 July. | The ERNIE Bot brand was folded into the Wenxin assistant; yiyan.baidu.com now redirects to wenxin.baidu.com. |
| 9 May 2026 | ERNIE 5.1 | About a third of ERNIE 5.0’s total parameters, at roughly 6% of the pre-training cost of comparable models. A preview had ranked first among Chinese models on LMArena on 30 April, and 5.1 ranked fourth worldwide on the Arena search leaderboard. | A strong search-arena score means Baidu’s answer model is competitive at grounded, web-backed answers. |
| 15 April 2026 | ERNIE-Image | Image generation model added to the family. | Image answers and generated visuals inside Baidu products. |
| 22 January 2026 | ERNIE 5.0 official release | Native omni-modal model with 2.4T parameters and under 3% active per token; available in the Wenxin app, the ERNIE Bot site and Qianfan. | Text, image, audio and video handled by one model, so video and images become answer sources in their own right. |
| 13 November 2025 | ERNIE 5.0 Preview | Shown at Baidu World 2025 as a preview. | Start of the 5.x generation that now sits under Baidu AI Search. |
| 11 November 2025 | ERNIE-4.5-VL-28B-A3B-Thinking | Open-source vision-language reasoning model. | Lightweight open model for reading images and charts. |
| 16 October 2025 | PaddleOCR-VL | 0.9B document-parsing model built on ERNIE 4.5, open-sourced. | Tables, formulas and layouts in PDFs become machine-readable at low cost. |
| 9 September 2025 | ERNIE X1.1 | Reasoning model update at WAVE Summit; Baidu claimed factual accuracy up 34.8% over X1. | Fewer factual errors in answers that cite or summarise sites. |
| 2 July 2025 | Baidu Search overhaul | The biggest search redesign in a decade: a “smart box” accepting more than 1,000 characters plus voice, image and file input, and an upgraded AI assistant. | Long, conversational queries replace keywords, and AI answers move to the centre of the results page. |
| 30 June 2025 | ERNIE 4.5 open-sourced | Ten model variants up to 424B parameters released under Apache 2.0. | Baidu’s models became available to any Chinese app, not only Baidu’s own products. |
| 25 April 2025 | ERNIE 4.5 Turbo and X1 Turbo | Faster versions; 4.5 Turbo 80% cheaper than 4.5 (¥0.8 per million input tokens, ¥3.2 output) and X1 Turbo 50% cheaper than X1. | Cheaper answer generation for Baidu and its cloud customers. |
| 16 March 2025 | ERNIE 4.5 and ERNIE X1 | Multimodal 4.5 and reasoning model X1, priced at about half of DeepSeek-R1; ERNIE Bot made free to individuals ahead of the 1 April date. | Baidu’s direct reply to DeepSeek on both quality and price. |
| 16 February 2025 | DeepSeek-R1 in Baidu Search | Baidu Search fully integrated DeepSeek R1 alongside ERNIE. | Baidu answers no longer come only from ERNIE, which matters when testing how a brand is described. |
| 13 February 2025 | ERNIE Bot to go free; deep search | Baidu said ERNIE Bot would be free from 1 April and launched deep search on it. On 14 February it said ERNIE 4.5 would be open-sourced from 30 June. | Free access put ERNIE answers in front of far more users. |
| 12 November 2024 | iRAG at Baidu World 2024 | Retrieval-augmented image generation and the no-code app builder Miaoda; ERNIE Bot reported 430 million users. | Search retrieval used to ground generated images as well as text. |
| 28 June 2024 | ERNIE 4.0 Turbo | Faster 4.0 at WAVE Summit; ERNIE Bot reported 300 million users. | Speed was the barrier to putting ERNIE answers on more queries. |
| 21 May 2024 | ERNIE Speed and Lite made free | Two lighter ERNIE models made free on Qianfan. | Baidu’s move in the price war that followed DeepSeek-V2. |
| 17 October 2023 | ERNIE 4.0 | New flagship shown at Baidu World 2023, with Baidu Search and other products rebuilt around it. | The start of generative answers as a standard part of Baidu Search. |
| 31 August 2023 | ERNIE Bot opens to the public | Available to everyone in China after approval under the generative AI rules. | The first time ordinary users could get ERNIE answers. |
| 27 June 2023 | ERNIE 3.5 | Upgraded model behind ERNIE Bot, with plug-ins and benchmark claims against ChatGPT on Chinese tests. | Plug-ins were the first step towards ERNIE calling search and other tools. |
| 16 March 2023 | ERNIE Bot (文心一言) unveiled | Chatbot shown and opened to invited testers. | Baidu’s answer to ChatGPT and the start of AI answers in Chinese search. |
| December 2021 (month only) | ERNIE 3.0 Titan | 260B-parameter model built with Peng Cheng Laboratory. | Showed Baidu could train very large Chinese models. |
| July 2021 (month only) | ERNIE 3.0 | 10B-parameter model trained on text plus a knowledge graph. | Knowledge-graph training is why ERNIE leans on entities. |
| 30 July 2019 | ERNIE 2.0 | Continual pre-training framework that beat BERT and XLNet on 16 Chinese and English tasks. | Better language understanding fed into Baidu ranking and question answering. |
| March 2019 (month only) | ERNIE 1.0 | Knowledge-enhanced language model that masks whole entities and phrases instead of single characters. | The base of Baidu’s semantic matching in search. |
Key model events
ERNIE began as a research model, not a product. ERNIE 1.0 in March 2019 and ERNIE 2.0 on 30 July 2019 were Baidu’s answers to BERT, and the idea that set them apart was masking whole entities and phrases rather than single characters. ERNIE 3.0 in July 2021 added knowledge-graph training, and 3.0 Titan in December 2021 scaled that to 260B parameters. For SEO, this is background, but it explains a habit that still shows in Baidu answers: ERNIE thinks in entities. Brand names, product names and people that Baidu Baike and the knowledge graph already understand get picked up more reliably than loosely described ones. Our explainer What is Baidu ERNIE? covers the basics.
The product era starts on 16 March 2023, when Baidu showed ERNIE Bot (文心一言) to invited testers. ERNIE 3.5 in June added plug-ins, the bot opened to the public on 31 August, and ERNIE 4.0 at Baidu World on 17 October 2023 became the model behind Baidu’s rebuilt products. ReadIsi tracked that period in our ERNIE 4.0 piece and how Baidu reinvented search. In 2024 the story became price. After DeepSeek-V2 set a very low price in May, Baidu made ERNIE Speed and Lite free on 21 May, released the faster ERNIE 4.0 Turbo on 28 June, and by Baidu World in November reported 430 million ERNIE Bot users. The DeepSeek model history shows the other side of that price war, and our note on the lightweight models covers the cloud angle.
Early 2025 was Baidu reacting to DeepSeek-R1. On 13 February it said ERNIE Bot would be free from 1 April (our report) and launched deep search. Three days later Baidu Search added R1 next to ERNIE, an unusual admission that its own model was not enough on its own. ERNIE 4.5 and the reasoning model X1 followed on 16 March, priced well below rivals, and the Turbo versions in April cut prices again. On 30 June Baidu open-sourced the ERNIE 4.5 family under Apache 2.0, reversing years of keeping its models closed.
The search change that matters most to site owners came on 2 July 2025. Baidu called it the biggest search overhaul in a decade: the search box became a “smart box” that accepts more than 1,000 characters plus voice, images and files, and AI answers moved to the centre of the page. Queries became long and conversational, and the job of a page shifted from ranking for a keyword to being chosen as a source. ReadIsi’s ERNIE and AI search analysis and our audit of Baidu AI answers found those answers lean on a small set of sources, much more than Google’s AI Overviews do.
The 5.x generation followed. ERNIE 5.0 was previewed at Baidu World on 13 November 2025 and released officially on 22 January 2026 as a native omni-modal model with 2.4T parameters. ERNIE 5.1 on 9 May 2026 was smaller and far cheaper to train, and ranked fourth worldwide on LMArena’s search leaderboard. That ranking matters here because it tests answers grounded in live web results, which is exactly what Baidu AI Search does. The brand also changed: from 25 June 2026 the ERNIE Bot website stopped taking questions and users were moved to the Wenxin (文心) site, which is where yiyan.baidu.com now redirects.
Since September 2026 the focus has been tools for publishers and agents. Baidu added AI Traffic Analysis to its webmaster tools on 16 September; one site’s data showed a million citations and 39 clicks. It also opened Search Widgets so sites can offer skills rather than pages. In late October Baidu listed its search API on Qianfan at ¥36 per 1,000 calls, then on 30 October offered a ¥4.9 promotion aimed squarely at DeepSeek’s new search API. Sina reported on 29 October that Wu Tian, the executive who presented ERNIE 5.0, had left Baidu, and that new ERNIE news was expected soon. No new model had been released by 4 November, and Baidu World 2026 is on 12 November. Ongoing coverage is in Baidu AI, Baidu SEO and Baidu Products.
Parallel histories: DeepSeek and Baidu algorithm updates. Last reviewed 4 November 2026.