Claude Sonnet 5 vs Mistral Medium 3.5

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% / 97.8%	100.0% / 93.5%	99.0% / 97.4%	93.6% / 97.0%	98.7% / 98.2%
Email triage	98.2% / 94.9%	98.2% / 94.5%	97.9% / 92.7%	—	—
Personal data detection	99.7% / 99.7%	98.9% / 99.8%	99.7% / 100.0%	—	—
Contract clauses	100.0% / 98.1%	100.0% / 100.0%	98.2% / 97.1%	—	—

Correct fields: Claude Sonnet 5 / Mistral Medium 3.5; 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 2.1 pp. Mistral Medium 3.5 is 2× cheaper.

Metric	Claude Sonnet 5	Mistral Medium 3.5
Correct fields	99.8%	97.8%
Error-free documents	99%	79%
Per 1,000 documents	$8.84	$4.37
To fix / 1,000	13	207
Speed (median)	3.2 sec	2.3 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Mistral Medium 3.5
Supplier	100.0%	100.0%
Supplier ID (EIN, IČO…)	100.0%	100.0%
Invoice number	100.0%	100.0%
Payment reference	100.0%	94.7%
Invoice date	100.0%	98.7%
Due date	100.0%	99.3%
Net by tax rate	98.7%	88.0%
Tax by rate	99.3%	98.7%
Total	100.0%	100.0%
Currency	100.0%	100.0%
Bank account	100.0%	96.0%

Documents where they differ

Gomez & Sons, LLC · 7855 · Scan · Claude Sonnet 5 11/11, Mistral Medium 3.5 9/11
Miranda-Vega Group LLC · 4959 · PDF text · Claude Sonnet 5 11/11, Mistral Medium 3.5 10/11
Raleigh Engineering Inc. · INV253511 · Scan · Claude Sonnet 5 11/11, Mistral Medium 3.5 10/11
Archer-Smith Group LLC · A-004846 · Scan · Claude Sonnet 5 11/11, Mistral Medium 3.5 10/11
Jon Miller · INV250236 · Clean image · Claude Sonnet 5 11/11, Mistral Medium 3.5 10/11

Invoice extraction · Czech (150 documents)

Claude Sonnet 5 is more accurate by 6.5 pp. Mistral Medium 3.5 is 2× cheaper.

Metric	Claude Sonnet 5	Mistral Medium 3.5
Correct fields	100.0%	93.5%
Error-free documents	100%	63%
Per 1,000 documents	$9.41	$4.69
To fix / 1,000	0	367
Speed (median)	3.6 sec	2.6 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Mistral Medium 3.5
Supplier	100.0%	90.0%
Supplier ID (EIN, IČO…)	100.0%	87.3%
VAT ID	100.0%	85.3%
Invoice number	100.0%	99.3%
Payment reference	100.0%	95.3%
Invoice date	100.0%	88.7%
Tax point	100.0%	86.7%
Due date	100.0%	90.7%
Net by tax rate	100.0%	99.3%
Tax by rate	100.0%	98.7%
Total	100.0%	100.0%
Currency	100.0%	100.0%
Bank account	100.0%	94.0%

Documents where they differ

Pavlík a Zeman s.r.o. · 25500457 · Clean image · Claude Sonnet 5 13/13, Mistral Medium 3.5 9/13
Hrubý s.r.o. · DB2500960 · Clean image · Claude Sonnet 5 13/13, Mistral Medium 3.5 9/13
Jiřina Švecová · 25401227 · Clean image · Claude Sonnet 5 13/13, Mistral Medium 3.5 10/13
Stejskal, v.o.s. · FV2600175 · Photo · Claude Sonnet 5 13/13, Mistral Medium 3.5 10/13
Slavěna Pospíšilová · 26200409 · Scan · Claude Sonnet 5 13/13, Mistral Medium 3.5 10/13
Stavsklad s.r.o. · 2025/1111 · Scan · Claude Sonnet 5 13/13, Mistral Medium 3.5 10/13
Michaela Strnadová · 25600363 · Scan · Claude Sonnet 5 13/13, Mistral Medium 3.5 11/13
Sedláček s.r.o. · 2025/0774 · Scan · Claude Sonnet 5 13/13, Mistral Medium 3.5 12/13

Invoice extraction · German (150 documents)

Claude Sonnet 5 is more accurate by 1.6 pp. Mistral Medium 3.5 is 2.2× cheaper.

Metric	Claude Sonnet 5	Mistral Medium 3.5
Correct fields	99.0%	97.4%
Error-free documents	87%	75%
Per 1,000 documents	$10.42	$4.72
To fix / 1,000	133	253
Speed (median)	3.8 sec	2.5 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Mistral Medium 3.5
Supplier	100.0%	97.3%
Supplier ID (EIN, IČO…)	100.0%	98.7%
VAT ID	100.0%	96.0%
Invoice number	100.0%	100.0%
Payment reference	100.0%	92.7%
Invoice date	99.3%	98.0%
Tax point	100.0%	90.7%
Due date	100.0%	97.3%
Net by tax rate	89.3%	98.0%
Tax by rate	100.0%	100.0%
Total	100.0%	100.0%
Currency	100.0%	100.0%
Bank account	98.0%	97.3%

Documents where they differ

Meier GmbH · 2025-0264 · Photo · Claude Sonnet 5 13/13, Mistral Medium 3.5 10/13
Bauunternehmung Schröder GmbH · 2026-0622 · Clean image · Claude Sonnet 5 13/13, Mistral Medium 3.5 10/13
Malerbetrieb Otfried Haas · RE-2025-00168 · Scan · Claude Sonnet 5 13/13, Mistral Medium 3.5 11/13
Christoph Haas – Hausmeisterservice · 2025-1432 · Clean image · Claude Sonnet 5 13/13, Mistral Medium 3.5 11/13
Druckerei Baumann GmbH · 2025-0324 · Scan · Claude Sonnet 5 12/13, Mistral Medium 3.5 13/13
Ostmetall GmbH · AN-2025-00580 · Clean image · Claude Sonnet 5 13/13, Mistral Medium 3.5 12/13
Hoffmann UG (haftungsbeschränkt) · 2025/1479 · Clean image · Claude Sonnet 5 13/13, Mistral Medium 3.5 12/13
Zimmermann & Schulz GmbH · RE11274 · Scan · Claude Sonnet 5 12/13, Mistral Medium 3.5 13/13

Invoice extraction · Spanish (100 documents)

Mistral Medium 3.5 is more accurate by 3.4 pp. Mistral Medium 3.5 is 2.5× cheaper.

Metric	Claude Sonnet 5	Mistral Medium 3.5
Correct fields	93.6%	97.0%
Error-free documents	77%	67%
Per 1,000 documents	$11.89	$4.75
To fix / 1,000	230	330
Speed (median)	4.0 sec	2.5 sec
Valid answers	95.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Mistral Medium 3.5
Supplier	94.0%	99.0%
Supplier ID (EIN, IČO…)	95.0%	100.0%
VAT ID	95.0%	94.0%
Invoice number	95.0%	100.0%
Payment reference	94.0%	93.0%
Invoice date	95.0%	100.0%
Tax point	95.0%	93.0%
Due date	95.0%	97.0%
Net by tax rate	79.0%	85.0%
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

Talleres Ibérica, S.A. · PF25/1188 · Clean image · Claude Sonnet 5 0/13, Mistral Medium 3.5 13/13
Losa Comunicación S.L. · A-2026-0862 · PDF text · Claude Sonnet 5 0/13, Mistral Medium 3.5 13/13
Centro de Formación del Sur S.L. · F2026-0167 · PDF text · Claude Sonnet 5 0/13, Mistral Medium 3.5 13/13
Hermanos Peral S.L. · F2025-0581 · Scan · Claude Sonnet 5 0/13, Mistral Medium 3.5 12/13
Centro de Formación del Sur S.L.U. · F2025-1424 · Scan · Claude Sonnet 5 13/13, Mistral Medium 3.5 11/13
Talleres Rozas Zapata S.L. · FV25-01486 · Clean image · Claude Sonnet 5 13/13, Mistral Medium 3.5 12/13
Academia Checa S.L. · F2025-0208 · Clean image · Claude Sonnet 5 13/13, Mistral Medium 3.5 12/13
Leyre Lladó Vall · F2025-1476 · Photo · Claude Sonnet 5 13/13, Mistral Medium 3.5 12/13

Invoice extraction · French (97 documents)

Claude Sonnet 5 is more accurate by 0.5 pp. Mistral Medium 3.5 is 2.3× cheaper.

Metric	Claude Sonnet 5	Mistral Medium 3.5
Correct fields	98.7%	98.2%
Error-free documents	96%	81%
Per 1,000 documents	$11.02	$4.81
To fix / 1,000	41	190
Speed (median)	4.4 sec	2.6 sec
Valid answers	99.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Mistral Medium 3.5
Supplier	99.0%	99.0%
Supplier ID (EIN, IČO…)	99.0%	99.0%
VAT ID	99.0%	98.0%
Invoice number	99.0%	100.0%
Payment reference	97.9%	94.0%
Invoice date	99.0%	100.0%
Tax point	99.0%	100.0%
Due date	99.0%	100.0%
Net by tax rate	96.9%	95.0%
Tax by rate	99.0%	98.0%
Total	99.0%	99.0%
Currency	99.0%	96.0%
Bank account	97.9%	98.0%

Documents where they differ

Établissements Blanc SAS · F-11122 · Scan · Claude Sonnet 5 13/13, Mistral Medium 3.5 11/13
Établissements Bertrand SASU · F2025-0066 · Scan · Claude Sonnet 5 11/13, Mistral Medium 3.5 12/13
Constance Martin – Rédactrice (EI) · FAC25080663 · Scan · Claude Sonnet 5 13/13, Mistral Medium 3.5 12/13
Nettoyage Christine Rivière EI · 2025-12-1174 · Clean image · Claude Sonnet 5 13/13, Mistral Medium 3.5 12/13
Guérin & Fils EURL · 2026-05-688 · Clean image · Claude Sonnet 5 13/13, Mistral Medium 3.5 12/13
Couverture Durand SA · F-11179 · Photo · Claude Sonnet 5 13/13, Mistral Medium 3.5 12/13

Email triage · English (US) (150 documents)

Claude Sonnet 5 is more accurate by 3.3 pp. Mistral Medium 3.5 is 2.7× cheaper.

Metric	Claude Sonnet 5	Mistral Medium 3.5
Correct fields	98.2%	94.9%
Error-free documents	84%	57%
Per 1,000 documents	$4.01	$1.47
To fix / 1,000	160	427
Speed (median)	3.8 sec	0.8 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Mistral Medium 3.5
Category	100.0%	100.0%
Priority	97.3%	63.3%
Sentiment	86.7%	90.7%
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

Cody Baldwin · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 7/9
Danielle Little · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 7/9
Russell Bates · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 8/9
Kyle Schwartz · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 8/9
James Arnold · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 8/9
Gene Everett · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 8/9
Laurie Knight · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 8/9
Dale Sanchez · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 8/9

Email triage · Czech (150 documents)

Claude Sonnet 5 is more accurate by 3.6 pp. Mistral Medium 3.5 is 2.5× cheaper.

Metric	Claude Sonnet 5	Mistral Medium 3.5
Correct fields	98.2%	94.5%
Error-free documents	83%	55%
Per 1,000 documents	$4.91	$1.95
To fix / 1,000	167	447
Speed (median)	4.7 sec	0.8 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Mistral Medium 3.5
Category	100.0%	100.0%
Priority	96.0%	63.3%
Sentiment	87.3%	87.3%
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

Simona Kolářová · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 7/9
Milan Kašpar · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 8/9
Eduard Stejskal · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 8/9
Alois Sedlák · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 8/9
Alexandr Kubíček · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 8/9
Lýdie Tůmová · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 8/9
Zuzana Brožová · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 8/9
Natálie Kratochvílová · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 8/9

Email triage · German (150 documents)

Claude Sonnet 5 is more accurate by 5.1 pp. Mistral Medium 3.5 is 2.9× cheaper.

Metric	Claude Sonnet 5	Mistral Medium 3.5
Correct fields	97.9%	92.7%
Error-free documents	81%	48%
Per 1,000 documents	$5.11	$1.77
To fix / 1,000	187	520
Speed (median)	4.3 sec	0.8 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Mistral Medium 3.5
Category	100.0%	100.0%
Priority	96.0%	56.7%
Sentiment	84.7%	78.0%
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

Irmela Warmer · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 7/9
Sibille Lehmann · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 7/9
Friedbert Hoffmann · Email · Claude Sonnet 5 8/9, Mistral Medium 3.5 9/9
Swantje Noack · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 8/9
Rosemarie Steuer · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 8/9
Alexej Sauer · Email · Claude Sonnet 5 8/9, Mistral Medium 3.5 7/9
Raymund Weiß · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 8/9
Luzia Drewes · Email · Claude Sonnet 5 9/9, Mistral Medium 3.5 8/9

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

Both are equally accurate. Mistral Medium 3.5 is 3.1× cheaper.

Metric	Claude Sonnet 5	Mistral Medium 3.5
Correct fields	99.7%	99.7%
Error-free documents	98%	98%
Per 1,000 documents	$3.50	$1.15
To fix / 1,000	20	20
Speed (median)	2.5 sec	0.8 sec
Valid answers	100.0%	100.0%

Accuracy per field

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

Documents where they differ

Margaret Mills · Text · Claude Sonnet 5 7/7, Mistral Medium 3.5 6/7

Personal data detection · Czech (150 documents)

Mistral Medium 3.5 is more accurate by 0.9 pp. Mistral Medium 3.5 is 2.9× cheaper.

Metric	Claude Sonnet 5	Mistral Medium 3.5
Correct fields	98.9%	99.8%
Error-free documents	92%	99%
Per 1,000 documents	$4.06	$1.40
To fix / 1,000	80	13
Speed (median)	3.2 sec	0.8 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Mistral Medium 3.5
Names	96.7%	98.7%
Email addresses	100.0%	100.0%
Phone numbers	100.0%	100.0%
Addresses	97.3%	100.0%
Dates of birth	98.0%	100.0%
National IDs	100.0%	100.0%
Bank accounts	100.0%	100.0%

Documents where they differ

Růžena Tichá · Text · Claude Sonnet 5 6/7, Mistral Medium 3.5 7/7
Jonáš Toman · Text · Claude Sonnet 5 6/7, Mistral Medium 3.5 7/7
Rudolf Konečný · Text · Claude Sonnet 5 6/7, Mistral Medium 3.5 7/7

Personal data detection · German (150 documents)

Mistral Medium 3.5 is more accurate by 0.3 pp. Mistral Medium 3.5 is 3.2× cheaper.

Metric	Claude Sonnet 5	Mistral Medium 3.5
Correct fields	99.7%	100.0%
Error-free documents	98%	100%
Per 1,000 documents	$4.40	$1.38
To fix / 1,000	20	0
Speed (median)	3.7 sec	0.9 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Mistral Medium 3.5
Names	98.7%	100.0%
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

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

Contract clauses · English (US) (150 documents)

Claude Sonnet 5 is more accurate by 1.9 pp. Mistral Medium 3.5 is 2.1× cheaper.

Metric	Claude Sonnet 5	Mistral Medium 3.5
Correct fields	100.0%	98.1%
Error-free documents	100%	87%
Per 1,000 documents	$5.04	$2.35
To fix / 1,000	0	127
Speed (median)	3.4 sec	1.1 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Mistral Medium 3.5
Provider	100.0%	87.3%
Provider ID	100.0%	100.0%
Client	100.0%	88.7%
Client ID	100.0%	99.3%
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%	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

Page Printing LLC · Raleigh Printing Inc. · Contract text · Claude Sonnet 5 13/13, Mistral Medium 3.5 11/13
Frontier Solutions Inc. · San Diego Office Products Co. · Contract text · Claude Sonnet 5 13/13, Mistral Medium 3.5 11/13
Boston Supply LLC · Summit Systems Corp. · Contract text · Claude Sonnet 5 13/13, Mistral Medium 3.5 11/13
Blue Ridge Services Co. · Foster Janitorial Services Corp. · Contract text · Claude Sonnet 5 13/13, Mistral Medium 3.5 12/13

Contract clauses · Czech (150 documents)

Both are equally accurate. Mistral Medium 3.5 is 2× cheaper.

Metric	Claude Sonnet 5	Mistral Medium 3.5
Correct fields	100.0%	100.0%
Error-free documents	100%	100%
Per 1,000 documents	$6.05	$3.06
To fix / 1,000	0	0
Speed (median)	3.6 sec	1.2 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Mistral Medium 3.5
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%	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%	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 · German (150 documents)

Claude Sonnet 5 is more accurate by 1.1 pp. Mistral Medium 3.5 is 2.6× cheaper.

Metric	Claude Sonnet 5	Mistral Medium 3.5
Correct fields	98.2%	97.1%
Error-free documents	87%	75%
Per 1,000 documents	$7.11	$2.76
To fix / 1,000	133	247
Speed (median)	4.3 sec	1.2 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	Claude Sonnet 5	Mistral Medium 3.5
Provider	100.0%	100.0%
Provider ID	87.3%	82.0%
Client	100.0%	100.0%
Client ID	89.3%	80.7%
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%	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

Haustechnik Braun UG (haftungsbeschränkt) · Nordbau GmbH · Contract text · Claude Sonnet 5 13/13, Mistral Medium 3.5 11/13
Hansawerk GmbH · Schreinerei Weber AG · Contract text · Claude Sonnet 5 13/13, Mistral Medium 3.5 11/13
Richter & Scholz e.K. · Köhler AG · Contract text · Claude Sonnet 5 13/13, Mistral Medium 3.5 11/13
Meyer AG · Hartmann GmbH · Contract text · Claude Sonnet 5 11/13, Mistral Medium 3.5 13/13
Maintec GmbH · Schreinerei Wagner GmbH · Contract text · Claude Sonnet 5 13/13, Mistral Medium 3.5 12/13
Neumann Consulting UG (haftungsbeschränkt) · Huber AG · Contract text · Claude Sonnet 5 13/13, Mistral Medium 3.5 12/13
Winkler GmbH & Co. KG · Berger & Fuchs e.K. · Contract text · Claude Sonnet 5 13/13, Mistral Medium 3.5 12/13
Maintrans GmbH · Nordbau AG · Contract text · Claude Sonnet 5 13/13, Mistral Medium 3.5 12/13