Claude Sonnet 5 vs Gemini 3.5 Flash Lite

Same documents, same prompt: where each model is right, what it really costs and how fast it answers.

At a glance

Task · documents	English (US)	Czech	German	Spanish	French
Invoice extraction	99.8% / 99.2%	100.0% / 99.5%	99.0% / 100.0%	93.6% / 98.2%	98.7% / 98.7%
Email triage	98.2% / 96.3%	98.2% / 95.8%	97.9% / 94.7%	—	—
Personal data detection	99.7% / 99.5%	98.9% / 98.1%	99.7% / 99.6%	—	—
Contract clauses	100.0% / 100.0%	100.0% / 99.9%	98.2% / 98.0%	—	—

Correct fields: Claude Sonnet 5 / Gemini 3.5 Flash Lite; the better one in bold. Click a cell to see the details.

Invoice extraction · English (US) (150 documents)

Claude Sonnet 5 is more accurate by 0.6 pp. Gemini 3.5 Flash Lite is 10.2× cheaper.

Metric	Claude Sonnet 5	Gemini 3.5 Flash Lite
Correct fields	99.8%	99.2%
Error-free documents	99%	92%
Per 1,000 documents	$8.84	$0.87
To fix / 1,000	13	80
Speed (median)	3.2 sec	1.7 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Gemini 3.5 Flash Lite
Supplier	100.0%	100.0%
Supplier ID (EIN, IČO…)	100.0%	100.0%
Invoice number	100.0%	100.0%
Payment reference	100.0%	96.7%
Invoice date	100.0%	97.3%
Due date	100.0%	99.3%
Net by tax rate	98.7%	98.0%
Tax by rate	99.3%	100.0%
Total	100.0%	100.0%
Currency	100.0%	100.0%
Bank account	100.0%	100.0%

Documents where they differ

Atlanta Office Products LLC · A-001328 · PDF text · Claude Sonnet 5 11/11, Gemini 3.5 Flash Lite 9/11

Invoice extraction · Czech (150 documents)

Claude Sonnet 5 is more accurate by 0.5 pp. Gemini 3.5 Flash Lite is 9.1× cheaper.

Metric	Claude Sonnet 5	Gemini 3.5 Flash Lite
Correct fields	100.0%	99.5%
Error-free documents	100%	93%
Per 1,000 documents	$9.41	$1.03
To fix / 1,000	0	67
Speed (median)	3.6 sec	1.8 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Gemini 3.5 Flash Lite
Supplier	100.0%	100.0%
Supplier ID (EIN, IČO…)	100.0%	100.0%
VAT ID	100.0%	100.0%
Invoice number	100.0%	100.0%
Payment reference	100.0%	95.3%
Invoice date	100.0%	100.0%
Tax point	100.0%	100.0%
Due date	100.0%	100.0%
Net by tax rate	100.0%	100.0%
Tax by rate	100.0%	100.0%
Total	100.0%	100.0%
Currency	100.0%	98.7%
Bank account	100.0%	99.3%

Documents where they differ

Sedláček s.r.o. · 2025/0774 · Scan · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13
Pavlík a Zeman s.r.o. · 25500457 · Clean image · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13
Sedlák s.r.o. · 20250158 · Photo · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13

Invoice extraction · German (150 documents)

Gemini 3.5 Flash Lite is more accurate by 1 pp. Gemini 3.5 Flash Lite is 10.1× cheaper.

Metric	Claude Sonnet 5	Gemini 3.5 Flash Lite
Correct fields	99.0%	100.0%
Error-free documents	87%	100%
Per 1,000 documents	$10.42	$1.03
To fix / 1,000	133	0
Speed (median)	3.8 sec	1.5 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Gemini 3.5 Flash Lite
Supplier	100.0%	100.0%
Supplier ID (EIN, IČO…)	100.0%	100.0%
VAT ID	100.0%	100.0%
Invoice number	100.0%	100.0%
Payment reference	100.0%	100.0%
Invoice date	99.3%	100.0%
Tax point	100.0%	100.0%
Due date	100.0%	100.0%
Net by tax rate	89.3%	100.0%
Tax by rate	100.0%	100.0%
Total	100.0%	100.0%
Currency	100.0%	100.0%
Bank account	98.0%	100.0%

Documents where they differ

Druckerei Baumann GmbH · 2025-0324 · Scan · Claude Sonnet 5 12/13, Gemini 3.5 Flash Lite 13/13
Zimmermann & Schulz GmbH · RE11274 · Scan · Claude Sonnet 5 12/13, Gemini 3.5 Flash Lite 13/13
Südform AG · 2025-0307 · PDF text · Claude Sonnet 5 12/13, Gemini 3.5 Flash Lite 13/13
Zimmermann UG (haftungsbeschränkt) · GS10958 · Clean image · Claude Sonnet 5 12/13, Gemini 3.5 Flash Lite 13/13

Invoice extraction · Spanish (100 documents)

Gemini 3.5 Flash Lite is more accurate by 4.6 pp. Gemini 3.5 Flash Lite is 11.3× cheaper.

Metric	Claude Sonnet 5	Gemini 3.5 Flash Lite
Correct fields	93.6%	98.2%
Error-free documents	77%	79%
Per 1,000 documents	$11.89	$1.05
To fix / 1,000	230	210
Speed (median)	4.0 sec	1.6 sec
Valid answers	95.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Gemini 3.5 Flash Lite
Supplier	94.0%	98.0%
Supplier ID (EIN, IČO…)	95.0%	100.0%
VAT ID	95.0%	83.0%
Invoice number	95.0%	100.0%
Payment reference	94.0%	99.0%
Invoice date	95.0%	99.0%
Tax point	95.0%	98.0%
Due date	95.0%	100.0%
Net by tax rate	79.0%	100.0%
Tax by rate	95.0%	100.0%
Total	95.0%	100.0%
Currency	95.0%	100.0%
Bank account	95.0%	100.0%

Documents where they differ

Hermanos Peral S.L. · F2025-0581 · Scan · Claude Sonnet 5 0/13, Gemini 3.5 Flash Lite 13/13
Talleres Ibérica, S.A. · PF25/1188 · Clean image · Claude Sonnet 5 0/13, Gemini 3.5 Flash Lite 13/13
Losa Comunicación S.L. · A-2026-0862 · PDF text · Claude Sonnet 5 0/13, Gemini 3.5 Flash Lite 13/13
Centro de Formación del Sur S.L. · F2026-0167 · PDF text · Claude Sonnet 5 0/13, Gemini 3.5 Flash Lite 13/13
Talleres Rozas Zapata S.L. · FV25-01486 · Clean image · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13
Climatización Levante S.L. · F2025-1305 · Scan · Claude Sonnet 5 12/13, Gemini 3.5 Flash Lite 13/13
Polo Soluciones Digitales S.A. · 2025/1068 · Scan · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13
Arranz e Hijos S.L. · F2026-0940 · Clean image · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13

Invoice extraction · French (97 documents)

Both are equally accurate. Gemini 3.5 Flash Lite is 10.3× cheaper.

Metric	Claude Sonnet 5	Gemini 3.5 Flash Lite
Correct fields	98.7%	98.7%
Error-free documents	96%	85%
Per 1,000 documents	$11.02	$1.07
To fix / 1,000	41	150
Speed (median)	4.4 sec	1.5 sec
Valid answers	99.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Gemini 3.5 Flash Lite
Supplier	99.0%	98.0%
Supplier ID (EIN, IČO…)	99.0%	100.0%
VAT ID	99.0%	100.0%
Invoice number	99.0%	99.0%
Payment reference	97.9%	91.0%
Invoice date	99.0%	98.0%
Tax point	99.0%	98.0%
Due date	99.0%	100.0%
Net by tax rate	96.9%	100.0%
Tax by rate	99.0%	100.0%
Total	99.0%	100.0%
Currency	99.0%	100.0%
Bank account	97.9%	99.0%

Documents where they differ

Clément & Fils SASU · 2025-04-431 · Clean image · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13
Établissements Michel SA · FAC25100622 · Clean image · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13
Établissements Bertrand SASU · F2025-0066 · Scan · Claude Sonnet 5 11/13, Gemini 3.5 Flash Lite 12/13
Constance Martin – Rédactrice (EI) · FAC25080663 · Scan · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13
SARL Garcia Informatique · F2025-0111 · Clean image · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13
Richard David EI · FAC25091009 · PDF text · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13
Catherine Dubois EI · FAC-2025-00139 · PDF text · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13
Gilbert Marie – Multiservices (EI) · FAC-2025-00924 · Clean image · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13

Email triage · English (US) (150 documents)

Claude Sonnet 5 is more accurate by 1.9 pp. Gemini 3.5 Flash Lite is 9.6× cheaper.

Metric	Claude Sonnet 5	Gemini 3.5 Flash Lite
Correct fields	98.2%	96.3%
Error-free documents	84%	69%
Per 1,000 documents	$4.01	$0.42
To fix / 1,000	160	313
Speed (median)	3.8 sec	0.7 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Gemini 3.5 Flash Lite
Category	100.0%	100.0%
Priority	97.3%	84.0%
Sentiment	86.7%	82.7%
Customer name	100.0%	100.0%
Order number	100.0%	100.0%
Invoice number	100.0%	100.0%
Amount	100.0%	100.0%
Currency	100.0%	100.0%
Deadline	100.0%	100.0%

Documents where they differ

Robert Lewis · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 7/9
Luke Sims · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9
Russell Bates · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9
Sheila Evans · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9
Jane Rubio · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9
Laurie Knight · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9
Daniel Stewart · Email · Claude Sonnet 5 8/9, Gemini 3.5 Flash Lite 9/9
Allison Floyd · Email · Claude Sonnet 5 8/9, Gemini 3.5 Flash Lite 9/9

Email triage · Czech (150 documents)

Claude Sonnet 5 is more accurate by 2.4 pp. Gemini 3.5 Flash Lite is 9.6× cheaper.

Metric	Claude Sonnet 5	Gemini 3.5 Flash Lite
Correct fields	98.2%	95.8%
Error-free documents	83%	64%
Per 1,000 documents	$4.91	$0.51
To fix / 1,000	167	360
Speed (median)	4.7 sec	0.7 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Gemini 3.5 Flash Lite
Category	100.0%	100.0%
Priority	96.0%	80.0%
Sentiment	87.3%	84.0%
Customer name	100.0%	98.0%
Order number	100.0%	100.0%
Invoice number	100.0%	100.0%
Amount	100.0%	100.0%
Currency	100.0%	100.0%
Deadline	100.0%	100.0%

Documents where they differ

Blanka Kučerová · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9
Simona Kolářová · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9
Petra Šťastná · Email · Claude Sonnet 5 8/9, Gemini 3.5 Flash Lite 9/9
Andrea Dostálová · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9
Adam Vaněk · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9
Šimon Beran · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9
Magdalena Sedláčková · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9
Dominika Šťastná · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9

Email triage · German (150 documents)

Claude Sonnet 5 is more accurate by 3.2 pp. Gemini 3.5 Flash Lite is 10.7× cheaper.

Metric	Claude Sonnet 5	Gemini 3.5 Flash Lite
Correct fields	97.9%	94.7%
Error-free documents	81%	57%
Per 1,000 documents	$5.11	$0.48
To fix / 1,000	187	433
Speed (median)	4.3 sec	0.8 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Gemini 3.5 Flash Lite
Category	100.0%	100.0%
Priority	96.0%	76.0%
Sentiment	84.7%	76.7%
Customer name	100.0%	99.3%
Order number	100.0%	100.0%
Invoice number	100.0%	100.0%
Amount	100.0%	100.0%
Currency	100.0%	100.0%
Deadline	100.0%	100.0%

Documents where they differ

Margret Löchel · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 7/9
Rolf-Peter Metz · Email · Claude Sonnet 5 7/9, Gemini 3.5 Flash Lite 8/9
Swantje Noack · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9
Raymund Weiß · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9
Sylwia Gerlach · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9
Cristina Krause · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9
Cynthia Hahn · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9
Sibille Lehmann · Email · Claude Sonnet 5 9/9, Gemini 3.5 Flash Lite 8/9

Personal data detection · English (US) (150 documents)

Claude Sonnet 5 is more accurate by 0.2 pp. Gemini 3.5 Flash Lite is 8.6× cheaper.

Metric	Claude Sonnet 5	Gemini 3.5 Flash Lite
Correct fields	99.7%	99.5%
Error-free documents	98%	97%
Per 1,000 documents	$3.50	$0.41
To fix / 1,000	20	27
Speed (median)	2.5 sec	0.8 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Gemini 3.5 Flash Lite
Names	100.0%	100.0%
Email addresses	100.0%	99.3%
Phone numbers	100.0%	100.0%
Addresses	98.0%	98.7%
Dates of birth	100.0%	98.7%
National IDs	100.0%	100.0%
Bank accounts	100.0%	100.0%

Documents where they differ

Matthew Ramirez · Text · Claude Sonnet 5 7/7, Gemini 3.5 Flash Lite 6/7

Personal data detection · Czech (150 documents)

Claude Sonnet 5 is more accurate by 0.8 pp. Gemini 3.5 Flash Lite is 8.9× cheaper.

Metric	Claude Sonnet 5	Gemini 3.5 Flash Lite
Correct fields	98.9%	98.1%
Error-free documents	92%	88%
Per 1,000 documents	$4.06	$0.45
To fix / 1,000	80	120
Speed (median)	3.2 sec	0.8 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Gemini 3.5 Flash Lite
Names	96.7%	91.3%
Email addresses	100.0%	100.0%
Phone numbers	100.0%	100.0%
Addresses	97.3%	99.3%
Dates of birth	98.0%	96.0%
National IDs	100.0%	100.0%
Bank accounts	100.0%	100.0%

Documents where they differ

Květa Kučerová · Text · Claude Sonnet 5 7/7, Gemini 3.5 Flash Lite 6/7
Jonáš Toman · Text · Claude Sonnet 5 6/7, Gemini 3.5 Flash Lite 7/7
Artur Musil · Text · Claude Sonnet 5 7/7, Gemini 3.5 Flash Lite 6/7
Jindřiška Bartošová · Text · Claude Sonnet 5 7/7, Gemini 3.5 Flash Lite 6/7

Personal data detection · German (150 documents)

Claude Sonnet 5 is more accurate by 0.1 pp. Gemini 3.5 Flash Lite is 9.7× cheaper.

Metric	Claude Sonnet 5	Gemini 3.5 Flash Lite
Correct fields	99.7%	99.6%
Error-free documents	98%	97%
Per 1,000 documents	$4.40	$0.45
To fix / 1,000	20	27
Speed (median)	3.7 sec	0.8 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Gemini 3.5 Flash Lite
Names	98.7%	97.3%
Email addresses	100.0%	100.0%
Phone numbers	100.0%	100.0%
Addresses	100.0%	100.0%
Dates of birth	99.3%	100.0%
National IDs	100.0%	100.0%
Bank accounts	100.0%	100.0%

Documents where they differ

Rosi Karz · Text · Claude Sonnet 5 7/7, Gemini 3.5 Flash Lite 6/7
Fritz Rogner · Text · Claude Sonnet 5 7/7, Gemini 3.5 Flash Lite 6/7

Contract clauses · English (US) (150 documents)

Both are equally accurate. Gemini 3.5 Flash Lite is 7.3× cheaper.

Metric	Claude Sonnet 5	Gemini 3.5 Flash Lite
Correct fields	100.0%	100.0%
Error-free documents	100%	99%
Per 1,000 documents	$5.04	$0.69
To fix / 1,000	0	7
Speed (median)	3.4 sec	1.0 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Gemini 3.5 Flash Lite
Provider	100.0%	100.0%
Provider ID	100.0%	100.0%
Client	100.0%	100.0%
Client ID	100.0%	100.0%
Contract type	100.0%	99.3%
Price (net)	100.0%	100.0%
Currency	100.0%	100.0%
Billing period	100.0%	100.0%
Effective date	100.0%	100.0%
End date	100.0%	100.0%
Notice period (months)	100.0%	100.0%
Late-payment penalty (% per day)	100.0%	100.0%
Governing law	100.0%	100.0%

Documents where they differ

Both models got the same number of fields right on every example document.

Contract clauses · Czech (150 documents)

Claude Sonnet 5 is more accurate by 0.1 pp. Gemini 3.5 Flash Lite is 7.1× cheaper.

Metric	Claude Sonnet 5	Gemini 3.5 Flash Lite
Correct fields	100.0%	99.9%
Error-free documents	100%	98%
Per 1,000 documents	$6.05	$0.85
To fix / 1,000	0	20
Speed (median)	3.6 sec	0.9 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Gemini 3.5 Flash Lite
Provider	100.0%	99.3%
Provider ID	100.0%	100.0%
Client	100.0%	99.3%
Client ID	100.0%	100.0%
Contract type	100.0%	99.3%
Price (net)	100.0%	100.0%
Currency	100.0%	100.0%
Billing period	100.0%	100.0%
Effective date	100.0%	100.0%
End date	100.0%	100.0%
Notice period (months)	100.0%	100.0%
Late-payment penalty (% per day)	100.0%	100.0%
Governing law	100.0%	100.0%

Documents where they differ

Elektro Vaněk spol. s r.o. · Fišer a.s. · Contract text · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13
Autoservis Tesař spol. s r.o. · Tiskárna Beránek s.r.o. · Contract text · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13

Contract clauses · German (150 documents)

Claude Sonnet 5 is more accurate by 0.2 pp. Gemini 3.5 Flash Lite is 9× cheaper.

Metric	Claude Sonnet 5	Gemini 3.5 Flash Lite
Correct fields	98.2%	98.0%
Error-free documents	87%	84%
Per 1,000 documents	$7.11	$0.79
To fix / 1,000	133	160
Speed (median)	4.3 sec	1.0 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Gemini 3.5 Flash Lite
Provider	100.0%	100.0%
Provider ID	87.3%	86.0%
Client	100.0%	100.0%
Client ID	89.3%	88.7%
Contract type	100.0%	100.0%
Price (net)	100.0%	100.0%
Currency	100.0%	100.0%
Billing period	100.0%	100.0%
Effective date	100.0%	100.0%
End date	100.0%	99.3%
Notice period (months)	100.0%	100.0%
Late-payment penalty (% per day)	100.0%	100.0%
Governing law	100.0%	100.0%

Documents where they differ

Hansawerk GmbH · Schreinerei Weber AG · Contract text · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 11/13
Richter & Albrecht e.K. · Elbmetall UG (haftungsbeschränkt) · Contract text · Claude Sonnet 5 11/13, Gemini 3.5 Flash Lite 13/13
Meyer AG · Hartmann GmbH · Contract text · Claude Sonnet 5 11/13, Gemini 3.5 Flash Lite 13/13
Winkler GmbH & Co. KG · Berger & Fuchs e.K. · Contract text · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13
Maintrans GmbH · Nordbau AG · Contract text · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13
Möller GmbH & Co. KG · Schreinerei Kaiser GmbH · Contract text · Claude Sonnet 5 13/13, Gemini 3.5 Flash Lite 12/13
Schuster Medien e.K. · Bäckerei Böhm GmbH · Contract text · Claude Sonnet 5 12/13, Gemini 3.5 Flash Lite 13/13