We tested 134 official government forms: 96% are fillable, 85% carry an XFA layer, 4% are flat.

1. 1

   85% of the forms carry an XFA package on top of their AcroForm fields.

   114 of 134 PDFs contain an /XFA entry: 67 of 68 IRS forms, 24 of 26 USCIS forms, 10 of 13 California court forms, and every SSA and VA form tested. None is a dynamic XFA form: all 114 also ship standard widgets, so Chrome, Firefox, Preview and mobile viewers render them from the AcroForm layer. The XFA layer matters when a filler writes only the AcroForm values and leaves the XFA data in place: Adobe Acrobat then reads the XFA data and can show the form as blank. Removing the XFA entry on save avoids that, which is what JustFill does when it exports a filled AcroForm.

2. 2

   Flat PDFs come from agencies you would expect to be further along.

   5 of 134 forms have no form fields at all: WH-347 (DOL), DS-3053 (State Dept), Form DS-64 (State Dept), USPS Form 1583 (Other US federal), Starter Checklist (UK HMRC). All 5 have a text layer, and 4 of them still contain an empty AcroForm dictionary, which suggests the fields were removed before publication rather than never added. No scanned, image-only form appeared in the set.

3. 3

   34% are encrypted, and all of them still allow filling.

   45 forms open with an empty user password but carry owner restrictions. Filling is permitted on all 45; modifying the document is denied on 44; adding annotations is denied on 16 (SF-15, FL-300, FW-001, FL-150, FL-341(D), CM-010, 130-U, Kindergeld KG1, FL-100, FL-110, FL-120, FL-165, FL-170, MC-025, MC-030, MC-031). USCIS encrypts 24 of 26 forms and the California Judicial Council encrypts all 13; the IRS encrypts 0 of 68. These bits are honored by viewers, not enforced by cryptography.

4. 4

   Half of the fillable forms name their fields with codes, not words.

   63 of 129 fillable forms (49%) have fewer than 10% of fields with a readable name; 61 of those are IRS forms, whose fields are called f1_1[0], f1_2[0] and so on. USCIS, SSA, VA and the newer California forms use names such as LastName or ClaimantSSN. For anyone mapping a spreadsheet onto a form, "fillable" and "mappable" are not the same property.

5. 5

   The median fillable form has 91 fields; the largest has 1,851.

   The 129 fillable forms hold 19,512 fields in total: 14,207 text fields, 5,029 checkboxes, 202 dropdowns, 58 radio groups and 16 signature fields. The mean is 151.3 because a few forms are very large: Form 709 (1,851 fields, 10 pages), Form I-129 (980 fields, 38 pages), Form I-485 (760 fields, 24 pages), Form W-2 (568 fields, 11 pages). The longest by page count are Form I-129 (38 pages), Form I-485 (24 pages), Form 1040-ES (16 pages). The smallest fillable form, Form G-1145, has 6 fields.

6. 6

   87% were produced with Adobe LiveCycle or Adobe Designer.

   116 of 134 files name a Designer product in their metadata, which is where the XFA packages come from. 120 files declare PDF 1.7, 13 declare 1.6 and 1 declares 1.5. The oldest printed revisions still in service are MC-031 (July 1, 2005), MC-030 (January 1, 2006), MC-025 (July 1, 2009), Form 8832 (12-2013).

7. 7

   9 of 137 issuer landing pages returned 404 while the PDF itself was still online.

   On September 2, 2026, the landing pages for Form 4506-C, Form 433-D, Form 14039, Form I-130A, Form 433-F, Form 433-A, Schedule 1 (Form 1040), Schedule 2, Schedule 3 (Form 1040) answered HTTP 404, although each PDF was still served from the agency document path. 2 EPFO forms (India) were unreachable from outside the country, and 1 HMRC form (SC2) is published as an online form only, with no PDF at all. Those 3 forms are counted in the total but not in the analysis.

134 analyzed rows and 3 rows with a status instead of a verdict. The CSV below carries the remaining columns: file size, PDF version, producer, revision, field counts by type and the permission bits.