# External URL file inputs still fail on Gemini 3.5+ (now 403 PERMISSION\_DENIED, was 429) after the Sep 4 "fixed" post

**URL:** <https://discuss.ai.google.dev/t/external-url-file-inputs-still-fail-on-gemini-3-5-now-403-permission-denied-was-429-after-the-sep-4-fixed-post/181749>\
**Category:** Gemini API\
**Tags:** bug, ai-studio, gemini-api\
**Created:** [September 7, 2026, 5:31pm UTC](https://discuss.ai.google.dev/t/external-url-file-inputs-still-fail-on-gemini-3-5-now-403-permission-denied-was-429-after-the-sep-4-fixed-post/181749 "2026-09-07T17:31:25Z")\
**Posts on this page:** 1\
**Showing post:** 4

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**Author:** ![take](https://d1dlmcr85iqnpo.cloudfront.net/user_avatar/discuss.ai.google.dev/take/32/148101_2.png) [@take](https://discuss.ai.google.dev/u/take)\
**Post date:** [October 2, 2026, 5:03am UTC](https://discuss.ai.google.dev/t/external-url-file-inputs-still-fail-on-gemini-3-5-now-403-permission-denied-was-429-after-the-sep-4-fixed-post/181749/4 "2026-10-02T05:03:22Z")

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Hi @Sai_Deepika_K, thanks for the fix.

I’d like to clarify the size limit, because it differs from the official documentation.

Your reply says external URL fetching works “for files up to 15 MB”, while the [File input methods](https://ai.google.dev/gemini-api/docs/file-input-methods) page (last updated 2026-09-23) lists **100 MB per  
request/payload** for External URLs and does not mention 15 MB.

Could you clarify the following?

1. Which limit is correct for external URLs on Gemini 3.5+ — 15 MB or 100 MB?
2. Or do both apply — i.e. 100 MB for the total of all files in one request, and 15 MB for each individual file?
3. Has the 15 MB per-file limit always existed, or was it introduced with the recent fix for the 403 PERMISSION\_DENIED issue?
4. Does the limit differ by MIME type (e.g. `application/pdf` vs `image/*`) or by model (e.g. `gemini-3-flash-preview` vs Gemini 3.5+)?
5. What error (HTTP status / error status) is returned when a file exceeds the limit? We would like to handle it explicitly and fall back to the Files API.

In any case, it would be very helpful if the documentation could be updated to match the actual behavior, since we size our upload limits based on it.

Thanks!

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_[View the full topic](https://discuss.ai.google.dev/t/external-url-file-inputs-still-fail-on-gemini-3-5-now-403-permission-denied-was-429-after-the-sep-4-fixed-post/181749)._