Brandwave

NotebookLM vs PDF.ai:Which is more popular?

In September 2026, NotebookLM had more branded searches than PDF.ai among AI PDF tools worldwide. NotebookLM had about 24.5 million branded searches, while PDF.ai had 14,800. NotebookLM made up 86.2% of all AI PDF tool searches we track, and PDF.ai accounted for 0.05%. When we asked ChatGPT and Google AI Overviews about AI PDF tools, NotebookLM appeared in three of the five answers and PDF.ai in none.

Among AI PDF tools worldwide in September 2026

Who do people search for more?

NotebookLM, about 1655 searches for every 1 for PDF.ai

NotebookLM 24.5M searchesPDF.ai 14.8K searches

Who does AI mention more?

NotebookLM, mentioned in 3 of 5 answers, PDF.ai in 0

NotebookLM in 3 of 5PDF.ai in 0 of 5

Who does AI recommend more?

NotebookLM, the only one of the two named

NotebookLM first in 3PDF.ai never named

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Top AI PDF tools in ChatGPT and Google AI Overviews

In three ChatGPT questions and two Google AI Overviews, NotebookLM was mentioned in three out of five: in all three ChatGPT answers, but not in either of the two Google AI Overviews. PDF.ai did not appear in any of the five answers.

Most recommended by AI

Brands get a higher ranking if they are mentioned earlier in the answers.

  1. Adobe Acrobat1st
  2. NotebookLM2nd
  3. ChatPDF3rd
  4. Humata–
  5. PDF.ai–
  6. AskYourPDF–
  7. Documind–

Mentioned by AI

Each dot is one answer, filled in when that answer mentions the brand.

  • Adobe Acrobat5 of 5Named in 3 of 3 ChatGPT answersNamed in 2 of 2 Google answers
  • ChatPDF5 of 5Named in 3 of 3 ChatGPT answersNamed in 2 of 2 Google answers
  • NotebookLM3 of 5Named in 3 of 3 ChatGPT answersNamed in 0 of 2 Google answers
  • Humata0 of 5Named in 0 of 3 ChatGPT answersNamed in 0 of 2 Google answers
  • PDF.ai0 of 5Named in 0 of 3 ChatGPT answersNamed in 0 of 2 Google answers
  • AskYourPDF0 of 5Named in 0 of 3 ChatGPT answersNamed in 0 of 2 Google answers
  • Documind0 of 5Named in 0 of 3 ChatGPT answersNamed in 0 of 2 Google answers

See every answer about AI PDF tools

5 answers

Not named in any answer:

Brands are shown in the order each answer named them. The survey took place in the United States on October 20, 2026.

Is NotebookLM or PDF.ai more popular in search?

This chart shows how often people search Google for NotebookLM and PDF.ai by name. Each line represents a brand's share of searches for all seven AI PDF tools we track, month by month, from English-language searches worldwide.

NotebookLM and PDF.ai among AI PDF tools worldwide, by month

Share of searches by month for NotebookLM, PDF.ai. The figures are in the table below the chart.

View monthly share of searches table
MonthNotebookLMAdobe AcrobatChatPDFHumataPDF.aiAskYourPDFDocumind
Oct 202567.1%27.6%4.7%0.23%0.28%0.08%<0.01%
Nov 202573.4%21.7%4.4%0.18%0.21%0.08%<0.01%
Dec 202579.8%17.7%2.2%0.11%0.16%0.05%<0.01%
Jan 202681.1%17.2%1.5%0.07%0.11%0.04%<0.01%
Feb 202679.6%18.7%1.5%0.09%0.11%0.03%<0.01%
Mar 202683.8%14.4%1.5%0.08%0.11%0.03%<0.01%
Apr 202687%11.2%1.6%0.08%0.1%0.03%<0.01%
May 202686.9%11.6%1.3%0.05%0.08%0.02%<0.01%
Jun 202685.3%13.5%1%0.05%0.08%0.02%<0.01%
Jul 202682.7%16.3%0.86%0.04%0.08%0.02%<0.01%
Aug 202685.1%13.9%0.86%0.05%0.06%0.01%<0.01%
Sep 202686.2%12.8%0.87%0.05%0.05%0.01%<0.01%

How has the NotebookLM and PDF.ai comparison changed over the last 12 months?

3 findings
  • NotebookLM was ahead of PDF.ai in every measured month of the 12 months ending September 2026.
  • Across the 12 months ending September 2026, NotebookLM’s share of searches among AI PDF tools worldwide moved from 67.1% to 86.2%, and its estimated monthly branded searches moved from 11.9M to 24.5M.
  • Across the 12 months ending September 2026, PDF.ai’s share of searches among AI PDF tools worldwide moved from 0.28% to 0.05%, and its estimated monthly branded searches moved from 49.5K to 14.8K.

How did search popularity change for AI PDF tools worldwide in September 2026?

2 changes

  1. In September 2026, NotebookLM gained share of searches among AI PDF tools worldwide, from 85.1% to 86.2%.

  2. In September 2026, PDF.ai fell from 4th to 5th among AI PDF tools worldwide.

How are branded searches counted?

3 search terms

Brandwave collects information about searches that people make online using NotebookLM’s and PDF.ai’s names. When viewed over time, estimated search volumes for these branded terms can be used to understand whether interest in the brands is growing, holding steady, or fading.

NotebookLM

2 branded search terms

  • notebook lm
  • notebooklm

PDF.ai

1 branded search term

  • pdfai

How the Brand Demand Index is measured

Other head-to-heads among AI PDF tools

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